In a threesome or a foursome why is it always OK for the women to interact but it is somehow taboo for the guys?

I'm sure you do know the answer. Because it is gaaaaaaaaaaaaaaaaaaaaaay, and since there is no such thing as bi, only gaaaaaaaaaaaaaaaaaaay or true man then you must not ever fall under the suspicion of being gaaaaaaaaaaaaaaaaaaaaaay if you want to maintain your manhood.

This is what it boils down to.

Guys are always afraid of being gay. Dassit mane. But also, I'm not sure how consistently true the premise of the question is. Gay stuff in threesomes probably also gets talked about less when it happens.