交尾結合 butt to butt copulation

we still don't have a tag for it, as far as i'm aware. see post #5522250, post #4868453, post #4199519, post #3921606 and others. what can we call it?

Isn't this called knotting? Many of those pics are already tagged as such.

No, knotting is used for any kind of knotted penis.

It's definitely something that should have its own tag, but I'm not sure of a good tag name for this. ass-to-ass penetration would risk having it being used for things like post #5199901 or post #5480519.

For canine reproduction at least, it seems another term is "tie" or "copulatory tie" for that stage of mating.