Fiance says im turning nephew gay..ADVICE?

Okay I always find him messing around in my make up (its all crack an crap ughh) and trying to dress up in my clothes in my closest trying to be the "diva" (me and my sister ALWAYS act like divas messing around). I'm the person that has my nephew for custody right now. So yea I usually wouldn't care but my fiance says me and my sister are trying to make him gay. Also he's turning 4 on the 4th of july, what do I get him? ADVICE PLEASE