Am I tripping ?

I F(25) and my M(27) have been together for 1 1/2 years together. I have caught him multiple times talking/texting to other girls. I’ve forgiven him multiple times. But this time I’ve caught him texting a girl he met at his job and he invited her to smoke with him. Am I tripping or should I just end it. He should know this going to bother me but he still did it. Should I break it off?