Obviously don’t want to put ideas in your head but usually if someone is accusing the other of cheating and you have done nothing to make them distrust you, they have cheated themselves and feel guilt so project it onto you! You deserve so much better than the insults and missing his own son’s birthday, it’ll be horrid at first but you sound better off without him. It’s so easy to go back to someone who isn’t good for you, think about your child and what would be best for them as well as yourself, do you argue a lot with them infront of the child, id it causing you to be upset infront of the child? If it would be better for you and your son without him being in a relationship with you that’s your answer xx
He sounds so immature. You’ve got every right to have some time for yourself and he’s old enough to make his own way around without relying on you to pick him up. Missing his sons birthday is a joke unless he had a valid reason but I doubt he did from the sounds of him, I’d honestly try and let him go it sounds like your better off without him anyway here if you need to talk!