Not sure if wholesome or concerning
Well... nothing inappropriate is happening. The dynamic the heroine and male lead have isn't prurient, because it's specifically through their interactions that the heroine realizes she can be a "regular person" rather than this "prince-type" others have cast her as ("In the Clear Moonlit Dusk" has a similar thrust, but both the heroine and male lead are high schoolers in that one).
Mark's pretty forward, but he's also extremely earnest. He's not calculating anything-- rather than angling to seduce her properly because he's expressly aiming towards a "future", he wants to keep this "present" going and thus does what he does simply because he likes Subaru. That's how his actions and thinking come off.
It just happens that Subaru is extremely weak to this earnestness.
I find that doubly cute. And triply funny. And that aside, she doesn't invite these displays of his.