What do you mean, “even when we’re not speaking?” I’m trying to get a sense of, is this like an on/off HS relationship, or are you adults who really fight and don’t speak to each other?
If you were in a serious adult relationship and all of a sudden your boyfriend starts spending a lot of time with a woman who you know he’s attracted to, and is talking to her for hours a day, like, yeah, that’s not great and definitely warrants a state-of-the-relationship conversation to figure out if you’re both really happy. Especially if you’re fighting a lot and giving each other the silent treatment, like it would seem that your relationship is on its way out.
If you’re in high school, I would say, look, you’re both young, you’re very new to relationships and both trying to figure out what works for you. High school relationships usually do not last. And it’s tough to have a healthy and lasting relationship if you both lack communication skills and a deep enough connection where you regularly don’t speak to each other. It’s just not that serious. And it sounds like he’s become kind of infatuated with someone else and it’s bothering you. If you tell him how it makes you feel, and what you want and don’t want, and nothing changes, I would say move on.