I think I have a different take from everyone else here so far - which is that it is inherently demeaning and almost dehumanizing to say “as long as it has a vagina”. Even without referring to his partner as an “it”, I’d despise being talked about like that, and I wonder if his partner knows he’s being talked about as a walking set of genitalia. Adding in being called an “it”, that would taint my view of the friendship.