Most Helpful Guy
We can't read minds, and most guys are kinda dumb on social cues as well.
If the relationship is platonic then the guy would most likely want to know if it changes on your end because then the friendship has changed.
If you're not dating but doing that "friends with benefits thing" then the guy would want to know because then the situation is different and the rules will have to change.
If you're actually in a relationship then he should want to know whether or not his feelings are being reciprocated.