In part one, like the very beginning, he showed that he does care about Team 7, but most Sakura fappers think Sasuke truly loves Sakura. Also this is part flippin 1. these are kids, romantic? WTF. anyone that pairs kids like that are a bunch of pedo especially since it isn't even that significant.
In part 2, Sasuke is a little bit more mature and a bigger pain in the butt but this time he actually can act differently based on whether he cares about someone or loves them.
In terms of caring about people as a friend, he would go above and beyond cutting ties with them. But being romantic, this is Sasuke were talking about. He's kind of screwed up so it is really hard to gauge.
But we were shown that he acted a real caring and loving human being when Karin was in trouble, even risking his life and the rest of the team just to save her.
But that doesn't fly as romantic to Sakura fappers so IDK. They think Sasuke repeatedly showing his intent to kill Sakura is romantic then this would mean Sasuke truly hates Karin.
Also IDK how your older bro poking you in the forehead and you doing it to a girl means it's romantic. If anything, I feel as if he is telling her that he is putting her into the bro-zone.
There's also that 100% confirmed DNA test that Karin is Sarada's mother and the fact that no one seems to be able to answer her simple question whether or not Sakura is her mother, even Sakura herself couldn't answer that.
So yes Sasuke in my opinion only showed his romantic side "once?" part 1 he asked Naruto to save Sakura, I don't count that as romantic though due to age and backstory, overall character development, etc. Kakashi said that they will only be successful if the are an entire unit and that's why he even bothered dealing with Naruto and Sakura in the first place like him sharing his lunch with Naruto when he was all tied up.
Although in part 2, there was no rule, he is his own person and does not care about other people and yet he still acted this way with Karin. There was no real obligation that was given to him like Kakashi gave Team 7 in part 1. This was the only time Sasuke behaved like a regular person, when Karin was in danger and for him to break character like that for her I would say is the most romantic thing Sasuke ever was.