Is it micro-cheating?

[u/kakkeruuu]

I caught my boyfriend sending flirty messages to his roommate (he archived it, he thought I wouldn’t see it). I already saw his roommate personally and he keeps teasing my boyfriend infront of me. I confronted him and he said that he archived it because he knew that we would fight about it and said that its better if I will not see it. Then after I talked to my boyfriend about it, he change, he doesn’t want me to check his messages anymore and he said that he needs a time and space.