Trouble

I'm having trouble with my sons father he is always in an out of jail an says he wants to marry me but still has his "ex" still going up an seeing him an I was told they were getting married an I seen it on her fb an he says no there not they were but I recorded r conversation an sent it to her an now he told me b4 he wants to marry me an have his family back but she keeps seeing him at the jail idk wat to do so lost help!!!!!