First of all, it is not the cleanest or the most hygienic body part of a man-it is literally a private part kept hidden for most of the day. Blowjobs are way more intimate-note everyone is willing to suck a dick. There is just something different when your cock is being inserted inside the mouth of another compared to just simply fucking his ass.
Blowjob is probably the best thing that men want their partners to do for them.
