The ferret one is cute tho I don't think he got off, fingers might be too rough, but he looks like he's enjoying it. I wonder if he could be sucked without having your face destroyed by his claws. Ferret nail trim? Probably wouldn't get the ferret taste out of your mouth for a month though lol
Rabbits look blowable, damn they're cute as hell aren't they?
Smallest thing (though not mammalian) I ever engaged with was a pet dove. He was cooing and making a fuss in his cage, so I reached in to pet him. He immediately mounted my hand and started furiously rubbing his cloaca on it. Intrigued, I let him do it of course and it didn't take long before he ejaculated a surprising amount of gooey opaque semen onto my fingers. I'd say it was a couple of cc's, which is something if you consider his relative body weight. Poor guy had been storing that up for a long time I guess.