Since year zero I have brought both my children (DD and DS) up to play with what they want and dress up in whatever they choose, with no regards to gender or colour. (Yes we did go through a phase of princess dresses and plastic heels with the DS 
). Granted my DS did gravitate towards Star Wars and superheroes but he did enjoy dolls and dress up.
However recently my DS(4) has started saying no to playing with dolls and pushing prams etc. Until come today my son refused to wear pink boxers, as they are a girls colour, apparently a family 'friend' had told him only girls wear pink and play with dolls.
Trivial I know but AIBU to want to tell this friend to keep their f*cking opinion to themselves!!!
Ps he does still like wearing sparkly nail polish but only on his toes.