
You're optimistic 'cause you can see his red blush lines behind the ear. In real life though bruh, he's going to the police box to report a perv (/TДT)/

From the interactions they had in the past, seme's already had a hunch the guy had some interest in him. He noticed because he also had interest with the uke. If both are not conscious with one another, realistically you just shrug it as a friendly interaction. And the red ear is for the readers. He already saw him blushed enough times because his gestures to make a shot.
If seme gets hurt 'cause of him again, hajime will lose his shit and take it out on the already distraught uke. It's better if uke's the one who gets hurt this time
(〜 ̄△ ̄)〜