Caught. .

So i was leaving the houae when i heard a buzz and it was bf's phone ot was a message from a dating sex chat website call wellhello.com and i saw that he was talking to other girls sexually and telling thwm to meet up to fuck. Iwas so mad and heartbroken. I confronted him and he said that it was cause he was bored and lonely. We live together and been together. For 3 years. He has nwver sone anyrhing like this. Idk what to do? Like forgive him. Talk to him or what??