Why he does this tells me he loves me then has other woman.?

Been in relationship long time,he cheated,broke up sends me flowers,calls me up and says I love you twice,asked me over to his place,he was out when he got a call from woman saying they were looking to hook up,i told her i was supposed to be his girlfriend she got upset at me he found out lied his way out of it ,i will not talk to him hang up when he calls,she called me a liar what i had told her was true but okay she can have him, i give up and plan on movig on. I am trying to make sense of this,Wants his cake and eat it too i guess,I am moving on had enough. Just wonder thats all where hes at.Oh well good luck to him.Your thoughts please.