Is this dangerous behavior? *edited*

I posted this before but it was hard to follow.

There’s this guy named David that I’ve been hooking up with. We aren’t together but he acts like a toxic boyfriend. I have an old coworker named Patrick. Patrick is in his 50’s and married. He made a flirty joke to me once 2 yrs ago when he and his wife were splitting. But I stayed out of their marriage and we just moved on from it. But David found out and couldn’t move on. Even tho we weren’t even talking when he made the joke. Didn’t want me talking to him, made me pick between him and Patrick, would want to listen to all our convos, it was bad. But Patrick moved locations and we stopped talking 6 months ago. David told me that if I become friends with Patrick again, he’ll quit talking to me. Yesterday, Patrick messaged me just asking how I was and to tell me that he left the company all together. I didn’t know, but David was looking at my phone and saw that I was talking to him. Later on asked me what we were talking to and why. He said he wants to know any time that Patrick reaches out to me. And then told me that he wants to know any time a guy hits on me or “messages me like that”. I tried to be understanding of how David felt weird with Patrick but I feel like him generally wanting to know when men show interest in me AND looking at my phone is creepy. Especially since he doesn’t want to be together.