@Jammydodger70 I completely understood your OP and the timeline.
i don’t believe this man was telling you not to come on the next club night.
I believe he was telling you he’d be there but was in a relationship. I think he was doing this so you could decide whether to carry on. He is clearly fine with being a cheat, so he’s put the responsibility for the decision on what happens next on you.
You absolutely should not be put off going by him, but it’s worth being aware that, if you do talk to him while there, his dickbrain will tell him ‘well, I told her I’d be here but I’m in a relationship, yet here she is anyway chatting to me, so she must be okay with it and still want to carry on’.
This would put you in a very vulnerable place in terms of physical safety because you’ll be alone.
So I’d go, but blank him completely, and if he sidles up, tell him clearly you’re not interested and he must not speak to you again. Then enjoy being with other people you have met there before.
If you don’t think you can do that I’d give it a miss this time.