Need To Vent

My boyfriend of almost two and a half year left his phone on the bed and went out. I told myself not to check it but its always something that tell you to check it still. So i checked it. He texted a female to tell her friend when he move back to town to tell her friend he wants to be with her again and misses her. Two and a half years down the drain😇 plus in 11days I'm having his son. I confronted him. And he said it's because of my smart mouth he did it😂 i wanted to act crazy but i couldn't do nothing but laugh. What would you do if you were in this situation?