There are 30 States with Romeo & Juliet laws that may mitigate age of consent/statutory rape situations if the age difference between the couple is not significant even if one partner is above the age of consent and the other is below  My mom and dad married at 17 & 19. My dad was no perve and my mom was not a naive little girl.  They grew up together and all of my GPs were good friends.  Mom and dad reconnected a couple of years after both families moved when my dad visited my mom's family when he was attended USMC tech school 35miles from my mom's family home.

Even with an age difference and one underage, most states have a caveat that a short age gap mitigates statutory rape violations.    A Jr is likely 17 or nearly 17 and a 19yo is only approximately 2yrs older.  So, odds are there is not a likely consequence if they are within a couple of years of the same age in a State with R&J laws.  

My bride was 16 when SS was born.  The Spermidiot was 23.  My ILs did not prosecute him. Unfortunately.  Him in prison and on the predator's list would have made life a whole lot easier for us.

That said, I have not been a Saint on this topic.  I dated a number of younger women in my dating years in my teens and 20s starting in HS. i also dated a number of older women some more than 10yrs my elder.  My Jr year of HS I dated a college Sr who was 5+  years my Sr.   My HS GF my Sr year was a Sophomore and 14.  I was 18 and turned 19 a few months before graduation she turned 15 a couple of months after my 19th B-day.  Age of consent was 17.  I was not perving out, we met, then we dated with her parents' consent.   That State also has Romeo & Juliet laws potentially mitigating statutory rape if one partner is under age and the other is not "significantly" older.  No clear definition of "Significantly" though so it could be a role of the dice. That State's R&J laws also include that someone `14 can consent to sex with someone 17.  Though an 18yo does not have a get out of jail free card if dating a 14yo.  Since it is not out of the bounds of possibility that some HS Freshman can be 13 or 14.  I was also a 5yr Sr as I had two Sophomore years.

My next relationship with a significantly younger GF was ~6yrs later with a young woman who was 18.  I was 24.   Then again when I was 26 during my divorce.  I was 26, she was 18. That young lady was relentless and .... legal since age of concent in that state was 17.  I met my bride of 30 years when she was 18. I was 29.  Not cruising high schools though. We met at university during her first semester and the last semester of my 11yr undergrad career.  She was a mom.  Not necessarily germane but part of the equation maybe.

One of my employees in NJ had dated his GF through much of HS. After he graduated, they had a weekend over the bridge in another State. Her dad pressed charges. He was convicted of statutory rape and for transporting a minor across state lines for sexual purposes.  He appealed several times and many years after his conviction he finally ran out of appeals and had to report to Prison.  They had been married for 8yrs and had 3 kids together all born after they married.  Even after they married and his FIL requested for the charges to be dropped he ended up in prison. He had already been convicted.  He was only in Prison for 6mos but that nearly destroyed his career. At that time my DW and I had been married for about 12 years and our age difference was nearly 3X that of my employee and his wife.  Though my DW was of age when we met. 

Hopefully this kid does not end up destroying his life and the life of his GF.  Back in the day, pre-internet, this type of thing did not get a whole lot of attention as young people in HS together dating even with a few year age gap was common if not the norm. 

Not that lying is the way to go. However, I would say that prevaricating in answering a direct question about sleeping with someone's daughter may not get a direct and honest answer.

I have never been asked by a parent if I was having sex with their daughter. If I had been asked when I was a teen, I likely would have answered with a resounding NO! because I was not confident enough to put that parent in their place. Besides, who wants to poke that bear by being a cocky shit about it.  Don't as, don't tell is the best side of discretion on this IMHO.  If I was asked in my 20s, I would have made it clear, respectfully, that it was none of that parent's business.  In hind sight, even if I was in HS or post HS and my GF was at the age of consent, I would respectfully inform the asking parent that it was none of their business.

Now for story time with Rags. 

My GF in HS was a sophomore. I was a Sr. I was a 5yr Sr and was 4 years and 2mos older so we had a 5yr age difference for a couple of months.  I did not know how old she was until her mom called and invited me to her 15th birthday party.  It just never came up.

We met when she was 14 and I was 18;  With school approval I had hauled my Middle School cadets to the skating rink for an outing one Saturday.  She and I met then.  We dated with her parent's consent.  The whole meet the parents, get the hairy eyeball from her mom and dad, grudging approval, standard dating progression. My stock improved with her parents when I got the call to help her dad cut piglets.  I am sure he was trying to freak out the city boy BF.  Little did he know both sets of my GPs had retirement farms and castrating piglets was something I had done a number of times.  I spent a number of weekend permits from school helping them on their farm, playing in the town softball tournament with her family, etc....

I drove a van in HS. Which cost me a notable number of dates when parents said hell no, when I was picking up a date. My friends affectionately referred to the van as the F-k Truck.  That vehicle got more miles in the school parking lot than it ever got on the road.  Classmates borrowing my keys was a regular event.  My only rule was use your own sheets and the vehicle does not leave the parking lot. I mainly dated college girls from the college town 40miles away, or girls from town and not female Cadets.  I did get called to the Commandants office several times for lectures on letting friends use my van for parking lot spicy sleep sessions with their Cadet GFs.  Participating in sexual activity in the barracks was a major deal and is why I was promoted to Battalion XO halfway through my Sr year when my Battalion Commander and my Battalion XO got busted with female Cadets in their room.  In a vehicle in the parking lot was a grey area and was a known treated as an unknown.  I was a bit less brazen and kept my extracurricular activities to hotels or off campus parking locations in the woods.

The story time event is that my Sr year GF and I had been dating for several months and I picked my GF up for a date.  I brought her home on time. The problem, it was butt cold. Like below 0*F cold.  I pulled up to her house, walked her to the door, hugged her goodnight on the porch and walked back to the van.  Her dad was on the porch.  Frozen to the window of the van was a used condom that I had not tossed far enough and had touched the window. Her dad started laughing while asking how we had enjoyed dinner and the movie. 

We dated the rest of the year and before I headed out for University out of State at the end of that summer, I spent a couple of weeks with her family.  It could have gone very differently in another State.  Fortunately AOC in that Sate in those days was and to this day is 14.  Depending on the age of the older partner.   Though with some confusing caveats.  

 Sex with a minor under 14 is illegal regardless of age differences.

Sex with a minor 14-16 is a felony unless the offender is under 21.

Sex with a minor 17 is a misdemeanor if the offender is under 21.

The age of consent is 17 years old. This means that people who are 17 or older can legally consent to sexual activity. 

Consent for people under 17 

People who are 13 or younger cannot consent to sexual activity with anyone

People who are 14, 15, or 16 cannot consent to sexual activity with someone who is more than 4 years older or who is 21 or older

People who are 17 can consent to sexual activity with anyone who is 14 or older

Statutory rape 

Having sexual activity with someone under 17 can result in prosecution for statutory rape

Having sexual activity with someone under 14 can result in prosecution for statutory rape in the first degree

Having sexual activity with someone under 17 when you are over 21 can result in prosecution for statutory rape in the second degree

Romeo and Juliet law

There is a "Romeo and Juliet law" that may protect some people from statutory rape charges.

If the internet had been a thing when I was a Sr in HS, I would have been paranoid as hell.  I was blissfully ignorant though I was below the legal hurdle, except for 2mos between our birthdays.

In hind sight, this is some scary shit that teens need to be made fully aware of and parents need to be all over their teens and post teens about.  Anyone in their 20s should be checking IDs of dates as due diligence. Just to be safe.  Though in some States that have no age caveats or R&J laws, even if the under age partner has a fake ID and you meet them at a bar or night club, prison is likely.

If I had it to do over again, I would be far more interested in cougars than age peers while in HS.  Heck, even in university. There  are some scary smart young-uns that get into college at crazy young ages.  Going to jail in hand cuffs instead of to your college graduation because your GF or BF ended up being a 16yo university student savant would suck majorly.  With dual enrollment programs where HS students can attend colleges for dual credit, things can get squirrely in a hurry if a person is not careful.

Not all that long ago I saw a documentary on a young woman who was in her mid 20s who had a genetic condition that pretty much stopped her from physically maturing at about 12yo,  Though insanely rare, this young woman looked like a normal 12yo, her voice was appropriate for a 12yo, etc.. She was an honors level university graduate and struggling to engage in a career.  She had the interests of a woman in their mid 20s, men, make up, travel, was into fashion, etc...  That young woman was incredible and lived pretty much in hell.  Though her friends and family were great and were huge parts of her life.

When I was in Jr High, what we called it before Middle School became a thing, there was a 19yo 9th grader in my school.  That guy was a thug.  He had a beard, rode a motorcycle to school, etc...  

Stuff can definitely get weird and cause legal risk even for someone who has no intent to take advantage of anyone.

If there was one, for damned sure I would have any pubescent and beyond boy kids I might have on it and preach the just say no, wrap it before you tap it, and no glove no love to reduce health risks.  

Even if I was a girl dad, I would depro or norplant the hell out of my daughter(s) with the same health risk lectures of no glove no love, and wrap it before you tap it.  IMHO to protect teens from parenthood while assertively pushing the wait until adulthood or marriage message is not a playing both sides of the issue.  The issue is protecting kids while effectively parenting.  IMHO, a parent hedging their bets regarding their kids maturing sexually is wise.  Teens of both genders are creatures of curriosity driven by raging storms of hormones that can cause a short circuit between their brains and their tender bits. Even highly involved observant parents can find themselves on the STB grandparent list.

So to speak.

I am not suggesting you throw your relationship away, simply that you disengage yourself legally from all of his financial responsibilities. All it takes is one accident, one car crash, and you suddenly find yourself having to pay all of his debt. Imagine how many other things he may have signed up for that you don't know about (yet).