I would have no problem refusing gently or otherwise, my husband, however, wouldn't say no if they showed up with a herd of elephants! omg, I just visualized that...
I choose my battles when it comes to hubby and inlaws. I shouldn't have to make the trip to their tiny smoke infested trailer for at least 2yrs now, God love'em, and should be able to retire to the bedroom whenever I feel like it during their visits for at least a year. Don't get me wrong, I do like them and enjoy their visits...but you know how it can be.
But yes, I do agree, not even if you are married to someone should you EVER give them animals unless they have SPECIFICALLY and RECENTLY requested them, and even then the purchase should be done WITH them not as a SURPRISE! Not to seem overly emphatic there, lol. Heck, I almost feel as strongly about any gift - that's why at Christmas Hubby buys his own, I buy mine, we wrap them, and just so we get that surprise/excited/xmas morn feeling, we each unwrap the others' presents on Christmas day, it's a hoot! We do buy each other stocking stuffers though. It has cut down alot on wasteful spending imo, and I think it makes us appreciate the little things we buy each other much more. We both get what we want, and makes less stress for me: no having to pretend I like something or worry how much money he spent on something or did he like what I got him.