Thomas had a "no pet-no children" motto when I met him. When the relationship turned serious and he asked me to marry him he knew my two cats came with the bargain. He comrpomised without it ever being brought up.
When I decided to get Lucy I called him to tell him I was going to pick her up and he said "you know the rule" and I said, "you knew how difficult I am when you married me". He met me at the breeders and has loved her every bit as much as I do from the day she came home.
It truly was a compromise for him and I think it is what makes our marriage strong. We both compromise on what we can because we want each other to be happy. He knows how much joy she brings me (and him also) and that makes him happy. "No pets" is one compromise I could never make and I'm glad I didn't have to choose because I wouldn't be with Thomas today were that the case. That's just me...
Best of luck in your decision