Would this be cheating?

So my boyfriend was honest with me and he told me that he sexted a girl (no pictures) but didn't get turned on which I think is a lie because then he was trying to talk sexy to me. He never ever sexts me when I ask him which is rarely and he's broken my trust for him two other times and it had to do with other girls. I talked to him yesterday about the sexting with this girl and was getting mad and he wasn't taking my anger and sadness seriously (he was laughing and thought it wasn't a big deal).Would this be considered cheating? I feel like it is because I feel so sad and hurt that he made such a poor decision.