AITA for following my boundaries and breaking up with my boyfriend?

Long story short, my boyfriend and I are back together, but he was upset because I abruptly broke up with him over text because I found him liking a porn star’s photo of herself with her cleavage out on Instagram and this was after I explicitly stated that I don’t want to date him if he wants to continue liking suggestive photos like that (he was doing it as a single man at the time and was his habit). He was starting to unfollow accounts at the time, but he said that he would’ve continued if I hadn’t caught him and that he didn’t think it was a big deal / didn’t take my boundaries seriously.

Even then, he still says that I should’ve talked to him calmly instead of breaking up with him over text.

Help me understand if I’m being unreasonable for following my boundaries?