Is the writer a woman? I think this is shoujo story with a male perspective with how stupid male mc seem.
"I want to keep you to myself" Suck a dick you selfish bastard.
This is indeed marked as shoujo manga. Not sure whether the author is woman or not.
Though I'm curious, are you saying that from a man perspective, a man shouldn't be selfish and want to keep his partner to himself?
I'm asking because I have heard stories where the man is overprotective of his partner, so I thought MC's behavior here wasn't shoujo manga exclusive.