Bruh

Let me tell you why he ain't a green flag:

first he enjoys teasing uke by making him embarrassed (giving big clothes and then giving a cup of water so the pants will drop and then making fun of the mess)

and messing with him (kick the table to spill the drink on uke and then play the savior, also hiding the fact that he's older)

getting unreasonably angry when uke doesn't want to tell personal information (grabbing the neck trying to force it out of him),

Constantly being too rough (keeps on pinching uke's cheeks although he says that it hurts),

Coercing into drinking the beer kinda,

And the sex scene, uke kept saying that he's scared, it's too fast, he's inexperienced, it hurts, he's tired but it's all well and good because he came right? NOT.

And I know it's story logic but NEVER PUT ICE INSIDE THE BUTT, that can seriously cause gangrene in some cells if the ice cube is too long in one spot, which can develop into necrosis, which needs to be treated by cutting off the affected part or else it keeps spreading and possibly killing a person.

Also uke got fired because of seme (seme saw the asshole in the store said something hurtful to uke and chose to beat him up, as can be seen by the burning red knuckles and slightly bloodied watch on his hand as he pats uke on the head afterwards). I know it was done to avenge for uke, but the repercussions are quite harsh compared to him leaving it be, or finding out where the asshole lives and fucking him up in a situation that cannot be traced back to uke.

And generally I don't like the constant teasing, dragging uke everywhere without much listening to him, since uke is a victim of severe bullying and thus may not be able to distinguish what is too much when it comes from someone who also shows him affection.

It is thanks to the fact that uke doesn't fight back much and somewhat condones this behavior that the story seems cute. Had he been a bit more sensitive and guarded this would be a whole different story.