Not actual bikinis, bikini panties, you can get both on cotton which is what i use

I just use a pair of bikini panties under a pair of boyshort panties and it works for me (though I figure the larger your package the harder that may be)

Fire

I believe femininity and masculinity are more of personality categories than anything else. Both having a beautiful bits and ugly bits, in femininity the beautiful is a purpensety (idk how to spell that) to care for others in a personal sense (ie caring and nurturing) whereas the positive aspect of masculinity is an inclination towards more material caring (ie protection and providing). The dark sides are related to the positive, with femininity struggling against an inclination to be emotionally manipulative while masculinity struggles to not be physically abuse and physicalyl and emotionally abandoning.

I believe it is important that an individual male female or individual somewhere in the middle determine what they are inclination is towards and focus on improving their positive impact on others and decreasing their negative impact

Also huge disclaimer the traits described are generalizations and do not apply to everyone

Also also, societal rules on femininity or masculinity are really stupid and arbitrary