do not cancel the cake, i understand you are hurt. just allow him go to the party with his baby mama. before he could come back, pack all your belongings and leave the house.
if he calls you when he's back, tell him you have gone to where u are welcomed. then hang the call and block him in all the communication channels.
it might be difficult but trust me u will pull over.
he still have a thing for his baby mama and just using you.
