What would you do?

When I went into early labor my fiance left work and came to the hospital and stayed for a couple hours then left and was supost to go home and go to bed but went to his moms house and got online and posted a add of craigslist for a women to sleep withhim and posted pics of his dick on there said your place or mine...I found out because he had done it that to me before and I decided to look under that date to see if he had done anything and sure enough he did...But he still swears to this day he didn't meet with anyone it was just to get off....What the f*** I really want to leave him my baby is 3 months old now and I still think about that.