boyfriend problems ?!

so a friend from my boyfriends school sent me a video of him fighting! and like 3 months into the relationship (9 months now) we talked about him fighting and for him to stop an all bc it wasn’t worth it. he agreed and didn’t do it for a while and then just about 2-3 hours ago my friend from his school let’s call him bob so bob posted on his instagram story a video thing of my boyfriend fighting with his instagram username tagging him in bobs story. my being a nosy bitch and worrying about my boyfriend watched it and sure enough it was a video of him fighting at school! 3 WEEKS AGO i texted him and asked him what it was all about and he jus said i didn’t want you to be mad but the thing is i’m not

mad at him fighting i mean i am a little bit but i’m more mad at him for not telling me :( and we had a big argument over it idk what should i do , any advise?