[Oh his ears are burning so much, but he can't actually look at Duo right now.]

Well, many canine breeds, including dogs and wolves, have a...knot. On their penis. That inflates. For catching and holding during mating. To make sure the female gets pregnant. They can't be separated until it shrinks.

[He says it very quickly but also stumbles over it a bit. The fastest and choppiest thing he ever said.]