Search Results: ex boyfriend is hanging out with his ex

So a year ago I met this man who I openly told I like who said he was still getting over his ex (which ended a few months before I met him). We took things slow to build a friendship. Going out of state on trips together, meeting his family, hanging out every week. Though now I want to take it to another level he's turned ice cold, never calls me (I have to make the plans), never ask me to hangout but says he cares about me. He acts like a boyfriend but doesn't want to be my bf. I might be wasting my time on a person who doesn't want a relationship.

When my boyfriend and I started officially dating, I made my boundaries for our relationship clear: I will not accept being called names, I will not accept being lied to, and I will not accept cheating. He said that he understood and had the same boundaries as me. Great! Or not...

I have known him for a long time and we've been friends for years. Because of this we share a big group of friends. One of the girls we hang out with used to be his fuck buddy/booty call. Whatever, but I told him I wasn't comfortable with the two of them hanging out alone any more considering their history. Because they were friends with benefits, even casual hang outs for them would be very similar to their old "dates." He said okay. Anyway, yesterday I found out that he's actually been hanging out with that girl whenever he told me he had been golfing with his brother. I told him that I was leaving and that I would be moving out of our apartment at the end of the lease (thank god it's at the end of the month) instead of renewing.
1) he lied to me: aka crossed boundary number one
2) he used that lie to cover for hanging out with his ex-fuck buddy who he had agreed not to see one on one any more (at her house no less).

He is now accusing me of being unreasonable and saying that I'm unfair because my "boundaries" were really an ultimatum. I think this is BS. I told him I wouldn't put up with it if he crossed my boundaries. He crossed them, the consequence is that he loses me. He said that it's an ultimatum because it's like he has to do what I say (not lie or hang out with her), or else i dump him.

Is that an ultimatum?

just background info: we're both 26, we've been together for 2 years, we live together.

I don't know if he hooked up with her/had sex with her or anything, but I don't even care anymore. He lied to me and betrayed me. I'm gone either way, but do you think this is just setting healthy boundaries or was I issuing an ultimatum?