If possible have you or DH ask your SS if he likes painted nails ( if possible one on one with the one he is most comfortable with)

If he dislikes it or explains social discomfort then get some nail polish remover then discuss with BM

If he doesn't then he either really likes it and awesome or maybe therapy is needed if theres too many behaviors aren't adding up

Plenty of boys wear mama’s shoes or experiment with cosmetics. It’s a phase. DD7’s little buddy likes to go with all of us for spa day and get mani/pedis. He gets a kick out of choosing pretty colors for his nails. 

My DD7 also likes to go out with her dad and work on engines or chop wood. Should I question her about if she REALLY wants to or if she’s feeling social anxiety because she’s doing “boy” things?

Boys are allowed to feel pretty. 

My daughter pushed her dolls around in her brothers Tonka trucks when she was 4.  Was that odd?   She also put makeup on her little brothers and dressed them in her clothes. Oh the horror!  youngest DS came home from preschool one day with each fingernail on his right hand painted a different color.  Did I think it was weird, yes, but only for the fact that they didn't ask parents permission before doing it not that my sons nails were painted. 

Don't be surprised if your son wants his nails painted or plays with your makeup sometime.  The worst if when they run around with your bra on their head and try to use your underwear as a sling shot.  None of my boys have come out as gay...yet, and if they ever did it wouldn't matter. I would happily go get mani pedis done with them.  

I find it odd that anyone paints their nails...like we're show ponies...all these weird things people do to artifically up their attractive quotient are just weird...like the two-inch cocker spaniel eyelashes everyone is wearing...or the six-inch, pinpoint stilettos people wear...or hair extensions -- gluing fake hair into your scalp???...that's...just...weird...

So, nah, I don't find SS's painted nails weird. He might be asking BM to paint his nails when she's painting hers.

The only time I’d have an issue with this is if SS didn’t like having it done. I knew a little boy who, at 4, liked to wear dresses & princess tiaras. So he got to wear dresses & princess tiaras, it wasn’t a big deal. 

When I was younger I used to prefer my brothers cars to my barbies, hated dresses, and would rather hang out with boys than girls. As an adult, I love dresses, wear makeup nearly every day (minimal, but it’s there lol), love doing my hair, and am as feminine and girly as they come. 

If it’s not harming anyone it’s no issue, I’d leave it be. Maybe he’d like doing his nails with you too!

The only reason it may be a little strange is because there is no girl/sister.

When my niece paints her nails, her little brother would always want his painted, too. It's fairly harmless, really. Kids like color and they like drawing and painting on themselves My brothers also liked to paint their nails when I was painting mine, play dress up with me, put bows in their hair...etc. They've both turned into very traditional, manly men lol. 

Maybe BM is painting her nails and SS wants to join in? If BM is suggesting it or isn't painting her nails, too...it might be a weird daughter fantasy she has going on...but it's still probably harmless. 

Her son, her choice. Just like he is DH's son and can choose to remove the nail polish, which I don't recommend unless SS asks for it to be removed or if it's chipped/cracking. 

There is as much harm in this behavior as there is in girls doing traditionally boy things. So, none. If the kid is crying or acting weird about it, then it would be good for Dad to talk to him and then talk to BM. But that is something I would recommend no matter the behavior.

Eh... My son (when he was around that age) would get jealous of me and my daughter painting our nails. So I would paint his too. He wanted them done until he was around 6. Once he started school I only did his toes so he wouldn't get made fun of by the big kids. He grew out of the phase but even if he doesn't, it really isn't a big deal. Let him paint his nails if it makes him happy, there is nothing wrong with it. People today are much more understanding of little things like this.

The Girhippo painted six-year-old YSS's nails pink just to get under Chef's skin.  Although the Girhippo has a daughter (SD) she was basically demonstrating  that YSS belongs to me and not you.  In this case it was not YSS asking for this to be done as he often had seen my nails done but never brought it up.  

We just ignored it so it wouldn't get the reaction that the Girhippo had hoped for.   Yss couldn't care less whether or not his nails were painted.  SD chewed her nails like the Girhippo and refused any sort of girly treatment as she viewed herself as the Tomboy.

I must today as a child I found boys toys much more interesting than girls toys.

My son is pretty boy-sy but he also went through a phase like that. One time we had a sitter and she painted his nails but couldnt find the nail polish remover. She cut out in a hurry, but I didnt care. He can't imagine it now, but he used to love that. 

It's kind of trendy right now where I live- boys of all ages painting their nails. I don't know. Unless BM is doing other things, like putting her little boy in dresses and referring to him as a girl, I wouldn't really worry about it.