One major reason why couples should shave their genitals and armpits is the climate - people sweat a lot in summer and it is not practically possible to have a shower before every intercourse. A sweaty genital is not even half as desirable as a clean and shaved one because the absence of hair means absence of bad smell. We find our respective shaved genitals very desirable and attractive as far as oral sex is concerned - so we are in for shaving. And, for God's sake, stop equating gay-ness to being shaved! What a joke!!!
Shaving not only looks better, but you also reduce sweatiness in that area, and of course you won't look like a Neanderthal. I shave my armpits as well to complete the picture. Women tend to like this hygene.
I prefer to shave the "under-carriage" and trim the hair above my penis. It just feels better to me. I like my girlfriend to shave the labia and trim the rest. Never was a fan of the stray hair in the back of the throat after pleasing my partner.
I have shaven all these areas of myself before - chest, stomach, pubes, butt, & legs. Ok, shaving the hairs on the genital areas does resemble being like it was before puberty but that's how some of us prefer it thou. It may seem & look unnatural but it is sexy too - to some of us anyway.