I think its a communication issue really. Yes, i'd be upset if someone said that to me but there could be many reasons for why he experienced that (tho saying it to her during their first time was a BIG mistake) but not communicating with each other and just one-sidedly breaking up out of the blue was not the answer either. But they were teens. Teens don't always communicate properly-heck, even adults have problems! So its not like its not realistic, just frustrating as a reader. I hope they actually talk it out and come to some kind of an understanding. And soon!
oh this is spicy ლ(´ڡ`ლ)