There is something primeval about sucking cocks, sucking them till the cum and then swallowing that warm milky substance that makes you want to do it all the time. I have a few "straight" married guys with families who need to shoot their stuff who visit me just to get blown and satisfied and to know that their cum doesn't go to waste, gets enjoyed and appreciated, and these are guys I am happy to be with and to demand nothing more than the pleasure of sucking them to completion.
It doesn't mean I don't enjoy giving and taking and kissing in other circumstances.