Personally, it doesn't bother me too much because I rarely notice it. If the dude's extra loud about it I find it distracting, but otherwise it's just part of the act of fucking.

That being said, there are a few male pornstars that completely ruin scenes for me based on their extreme need to be heard. Nick Manning is one, no need for a tagline, just bust on that bitch's face and be done with it. Also, Lex Steele is entirely unbearable. He sounds like he's about ready to die, and I'd be astounded if he was doing it for the ladies, as I didn't realize the mating call of the hippopotamus was such a turn on for human females.