I don’t think it’s sexual; he doesn’t have an erection when he’s doing it. Plus, he’s fixed, if that makes a difference.
Is it just pure play? Does he see the toy as a living thing, and is trying to assert dominance over it?
He ain’t doing it for my entertainment, although I nearly laughed until I bled internally the first time I saw it.
Maybe it’s because he finds your leg unattractive…
I never thought of that… Maybe I should feel jealous!
just kidding.
complete WAG here, but my vote would be for the dominance thing. A friend of mine used to try to use this techique (asserting male dominance) at bars. If someone would start getting huffy, he’d yell “Don’t make me come over there and hump you!”
I’d like to nominate myself for most worthless post of the day.
If the stuffed animal in question is shaped like a leg, you certainly should! (Feel jealous, that is)
My dog Deej used to hump a Lurky, a stuffed toy that was a character from the old “Strawberry Shortcake” cartoon. First she’s growl and bite and whip it all over the place, and then she’d hump it. You always hurt the one you love.
Some year later, she and our new bog, Bingo, would take turns humping a Popple, a stuffed toy that could be tucked into itself. Bingo is male. So I don’t know what the hell was going on there.
I always got the impression that they didn’t even know why they were doing it. They always looked confused and guilty, as if to say, “I don’t know why I’m humping this thing, but I just can’t help myself.”
Dog psychology is murky at best. With my dog Ivy, it was always the laundry basket (full of laundry, no less!) Wow, that rhymed…
My girlfriend’s dog, a fixed female, humps the male cats. She bites at them and throws them around like she’s playing with them, then positions them with her forepaws, and start humping away. The strange thing is, she always did it to one cat, who is about four years old, but the other, who has just matured, she waited until he was fully grown before she started in on him. I always assumed it was sexual, but maybe it is asserting dominance.
Yeah, my cousin’s dog, he (the dog) does the growling thing, with his dogbed. He is very protective of it, and has been fixed, so whenever he does it, he can’t get an erection. He’s also VERY attached to it…he loves it. 
More than me, I’m afraid…
I’m not so sure the dogs are erection-less because they are fixed. I think my dog was “flaccid-humping” stuff before he was fixed. I can’t say for sure though, that was before he was living with me.
We have 2 dogs - both spayed females - and the dalmatian will often hump the border collie. I’ve been told it’s the dominance thing. But they both regard me as the alpha-dog, and I’ve humped neither. Does that mean I’m the biggest bitch??
I prefer to think that I’ve bought their loyalty with doggie biscuits…
My friend had a big stuffed sheepdog that she kept on her bed. It was huge and fluffy. Her cat used to NURSE the thing, pushing on its belly and suckling the fur. It was sooo cute!
At times my dog would hump the recliner. Not just any old time though, someone had to be in it and pull the lever to get it to recline. If my dog would hear it recline he’d come walking over and position himself and start going to town, gnawing on it and everything. He’s a crazy dog.
I knew a female Jack Russell terrier who used to hump a stuffed animal-- the owner’s vet had told her that it was a show of dominance. The dog was more likely to perform the trick if there were guests over that needed impressing/ a demonstration of her power over other [stuffed] animals.
I had an uncut male toy poodle named Max. He had a Cola-Cola bear that was bigger than he was, and first he would beat the shit out of it, and then hump it furiously. He would also wait until we had company to go to town.
Max did get erections while humping the bear though. Sometimes, it was no bigger than a little pink lipstick. Other times, it was a huge, disgusting red dog-erection. One time he had such a bad hard-on that he stood there crying, his penis touching the ground. I kind of felt he had an extremely long penis for such a small dog, but then again, I am no dog penis expert.
Rose
I heard that some dog trainers will ‘mount’ their trainees to assert dominance and get them to obey, but of course this isn’t something they make well known. 8^)
Dogs can get erections even if neutered.
Sometimes sexual behavior is play, sometimes it is dominance, but sometimes it is plain old masturbation. Yes, our sweet little pets do THAT.
Michi
I’m sorry, but this post made me laugh uncontrollably.
Especially the last few lines.
–Tim
That would be an interesting name for a band, perhaps!