Should I just walk away?

I was in a very long relationship. Almost seven years. We took a break because the arguing was too much, we had some space and came back to each other. We decided to go slow and slowly work our way back to things. Last night he was in his friends live thing he does and there is this girl we always have had problems with, she said she loved him and he said love u too and he said “he said it just to go along with the chat” and then she was making some very out of line comments about him and he played along. I love him so much but I don’t want to play games especially when we are twenty one. What would you do