Did the father get awarded any more time than 6 days a month? Some women fight to have their ex get as little as possible.  Is he paying child support through the nose and needs to work those 4 days that he has his son?  Lots of those stories on here.

People have a biological connection to their parents, and you will never be as important to the child as his father is. Period.  Even if he cares about you a great deal.

And please be careful - you are bordering on parental alienation with your need to marginalize the father and make yourself the important person in your SS's world.

I have been Dad to my SS-26 since shortly after his mom and I started dating when he was 15mos old.  His call. No one referred to me as Daddy.  He did that on his own.   I was the first person he ever called Dad(dy).   I raised him as my own.

He always had visitation with  his BioDad and the SpermClan.  We never lived nearer than 1200miles to them so visitation was long distance and included 7wks per year (5wks summer, 1wk winter, 1wk spring).  Over the course of that seven weeks of visitation he saw his biodad an average of less than 2 days in the summer, winter, or spring.  Even though his BioDad never demonstrated that he gave a shit about his eldest of four all out of wedlock children by three different baby mamas on several occassions over the years we paid for their visitation travel costs so that the kid could maintain contact and a realtionship with that part of his family.  SS saw that his mom and I cared enough to cover the SpermDad's responsibilities to his eldest child.  SpermDad never paid a penny in CS for his eldest. SpermGrandHag and SpermGrandPa paid their idiot son's responsibilities to his eldest, and to #2, #3 and #4 for that matter.

Though we never badmouthed the SpermIdiot and SpermClan to SS neither did we tolerate any manipulation or crap from them.  We kept SS tuned with the facts of the entire situation in an age appropriate manner over the later half of the 16+ years we lived under his Custody/Visitation/Support CO.  He knew when they lied and he knew that he could get the truth frofm his mom and I and from the volumes of court records, police reports, etc, etc, etc... that were in our home office.  As he got older there were many occassions when he would do his own research on something the SpermClan was feeding him that did not pass the smell test. 

My advice is, that if you are in an equity life partnership with his mom, for you to keep being his dad. Raise him as yours. Take the actions of love and raise him to be a man of character and standing in his communtiy.   Do what you can to counter the lack of engagement from his BioDad and to model a strong, confident, envolved father, husband and man.  So not bad mouth that part of his family and do not expect excitement and apprciation for what you do.   The excitment and thanks will come eventually.  My SS asked me adopt him when he was 22. We made that happen.  Now he has our family name on his chest as he serves our country.

I am one proud dad.

Take the actions, the feelings and results will follow. Eventually.

Remember to check your ego. 

Do you really need this kid to love you the way he loves his own father? Is that a fair expectation? 

Because trust me, chances are, if you have your own biological kid in the future, you won't love them the same. The biological bond between parent and child is strong. Incredibly strong. And it's not fair to expect anything of him that you can't give back. You're an adult who chose to be with someone with a child. Unfortunately, that comes with some sacrifices, like higher grocery costs and the occasional story before bedtime. That doesn't mean you've earned the kind of love a child can't usually give to anyone but their mom and dad. 

We don't like expecting stepparents to love their stepkids the same as they'd love their biological kids. We, on this site at least, know that it's an incredibly ridiculous and unfair expectation. It goes both ways. Look, I know it's hard... My stepdaughter's BM is barely involved, but she still loves the hell out of her because that's her mother. I do ALL of the "mom" work and get NONE of the credit. But that's life. I chose it. 

Once I had my 15-month-old son, I found it a lot easier because I could see that my love is truly different for her than it is for my son, so why should I expect anything more from her love for me? It's just not fair or possible. Step-situations are awkward at best for all involved, so we're kind and friendly to each other but not much else.  

I deal with it by not comparing my relationship with the children to their relationship with their mother. I respect that she is their mother and they will always love her. I don’t feel that them being happy to see her takes away from them being happy with me. I don’t feel it’s a competition.

Parents do not get "noticed" and are just those regular, everyday people who are there--sometimes in the background, sometimes in the foreground--but can be counted on as there all the time. It is an expectation of the child since they have learned that it is consistent.

His biological father is exciting because it's out of the norm, just like seeing cousins or a grandparent who is only seen occasionally. When he was about your stepson's age, my son loved, loved, loved when his grandmother would come to visit and thought it was super special. Then she lived with us for a while and he told me outright (privately) that she was boring and normal now. LOL