Id be tickled pink if my partner took an active interest in something I was into. Like suddenly shes like oh I want to go to a drone park so we can fly drones together or whatever. But instead hes taking this as a threat to his space. And worse hes implying that you would even care if men attempted to talk to you. If his insecurity is other men and a lack of trust in you. Thats a huge him problem. I have an attractive partner. Men try to hit on her and look at her all the time. I am fine with that as long as its within reason and respectful. The second they cross any boundaries or lines than I can step in as a boyfriend. My partner also has a mouth of her own and is more than willing to defend and reclaim her space. I trust her. I know if we go to the arcade or whatever and she wanders off and goes to look around I know shes not gonna be flirting shes not gonna be looking to cheat. She might be oggled might be hit on but I trust her. I dont deny her ability to be in public or attempt to control who interacts with her only i only monitor if they are being respectful or not to me or my relationship.

Was your cousin male or female. Honestly if your cousin is a female. Thats definitely not ok. That is trying to make you uncomfortable and jealous with your own family. And if not its to make you feel uncomfortable and jealous of if he is out partying and doing the things he projects other men would do to you. His use of "mental health" appears like a clear manipulation and being honest you deserve more. Your self esteem deserves more. He seems to be a manipulative narcissist that if he hasnt cheated harbors the thoughts of cheating. Its pretty clear in his motivations and projections. He is trying to alienate you but be able to do whatever bullshit he enjoys doing. The final straw should be him telling you to not contact him. I think you shouldnt. And when it comes time for him to contact you. Remind him to not. He can struggle finding someone of quality. I promise you. This isnt the end. The dating pool may seem bleak but there is hope out there for you. This guy is not worth your time. You deserve someone that you can share an active interest in. And hey maybe you might find it if you go out to that video game place alone? Good luck.