This is why I an open-minded boyfriend/husband. I can suck his cock while his dog fucks me from the back. I want to be double team by two horny men. (Bf and Bf's dog)
The only way I’d have a girlfriend is if she was an active zoo and encouraged me to be active as well but I know the odds of that happening are practically nill so I’ll just stick with animals and occasional one night stands with human women.
As others have said, if everybody relevant is consenting to it, the more the merrier! ^^
My own girlfriend isn't into it, and obviously I'll respect it, but I do sometimes wonder what the experience would feel like...
I know that long term I'd have some heavy sexual frustration if my girl isn't into my kinks, so like mentioned above, I'd only really go for women who are into what I'm into