I've known my ex boyfriend for many years to say hello to and over the years he has asked me a few times to go for a drink with him to which I have refused because at the time I was already in a relationship. However, he asked me again two years ago and this time I was single so accepted his offer. He told me he had been in an on off relationship with a woman for two and half years and that they were always breaking up. We started to date and then he started to fall out with me over the slightest things. We started to also have an on off relationship and twice I have ended it and he has gone back to her. I got back with him for the last time four months ago after he had chased me for a long time and I was convinced his mind was made up and it was in fact me that he wanted once and for all. We were very close so I thought but one morning he got up for work and started a silly argument and left. He never spoke to me again which was very odd for him. I found out the same week we split that he had in fact gone straight back to her. Has this man got serious issues of being torn between two or am I really that gullable?? Please help!!

To the OP. I think it's both. He has serious issues, and you're gullible. You need to find someone that wants to be with you, and only you. He's playing games, and you're letting him. Wouldn't you like a relationship with someone that wants to be with you, chooses to be with you, and is an equal partner in the relationship?

This guy isn't, and never will be. Let him go, and if he comes back, slam the door.

You're his fall back girl. He doesn't really want to be with you, but you're better than being alone. Three strikes - you've heard the phrase, right? You should no longer have time for him. He's had his chance, and even if he stuck by you the fourth time around, you'd never trust him to stay and it would be miserable to be with him - cut your losses and let him be someone else's shady problem.

He is using you, leave him.

Three times, you need to get a clue. Let him stay gone. The reason he does it is immaterial.
He is not reliable.