Ending FWB. AITA?

At 43 years old I never thought I’d be dumb enough to get into this situation. I met this guy about 3 months ago and we have hooked up semi-regularly and we talk/text almost every day. From the outset we agreed to be FWB. He’s not ready for something more serious at this point and I get it.

However, we had plans recently to hangout he changed plans at the last minute - all good, life happens. Later that night, I get a text from a mutual friend saying she is at a bar and the FWB is making out with another dude. He told me he had to go home for the night and couldn’t meet up.

From lurking here for awhile let me say that yes, I know we aren’t exclusive and can sleep with whomever we want. That isn’t what is eating at me - it’s the fact that he blatantly lied to me.

AITA for texting him that I need to end the entire relationship and to do it without saying why?