Unless a guy is really into you and willing to sacrifice his other options for you and commit to you, then exclusivity generally isn't going to be brought up by a guy.

In all the relationships I've had and that I've been aware of, the woman is usually the first one to bring it up. The thing about social dynamics is that when it comes to intersexual relations, biology fuels a lot of the psychology behind interactions.

A woman wants a man to commit to her whereas a man's biology goes against commitment. Social conditioning and culture have shifted a man to focus more on that than focusing on his biological impulses, but not so much that the majority of men will be the ones to initiate.

You're dealing with Bumble and Tinder. These are prime tools in this day and age for a man to seek casual sex and fulfill sexual urges.