Baby father a cheater

At the time my SO and I were dating for a little over a year. I put trust in him but one day a girl called my phone and told me she was pregnant by him. Paternity test proved it was his. We broke up and 3 weeks later i came back to him and we started having sex again. Well one month later into me coming back i got pregnant too. He will now have two babies 6 months apart. I try to make this not bother me but it does everyday.