I just found out one of the people I’m dating is cheating on me and I know that sounds so stupid even to me but the three of us had one simple rule you can date anyone you just have to let the rest of us know and he broke it I just I don’t know if I can leave I found out he was cheating because the other person broke up with him and called me to get me to check on him to make sure he wasn’t going to kill himself … just don’t know what to do.
Suicide threats are very serious. You are not his doctor, therapist, or emergency responders, and it is not your responsibility to keep someone from killing themselves. When things are at that point, you need to get professionals involved. If he, or anyone else, does that again, let him know what you can and cannot provide, and encourage him to call a suicide hotline or a healthcare professional. If he refuses, it is always okay to call for professional help yourself.
Someone threatening suicide is in crisis and it is not a crisis you can or should handle yourself. It feels shitty and miserable and dramatic to call 911 on someone you care about, but it is not overreacting, it is the right thing to do. Either he means it, and he is really at risk, which means he needs professional help; or he does not have a strong intention to kill himself, in which case you are the person at risk, and you need to redirect him to professionals who can help him handle whatever feelings are causing him to try and get his needs met by manipulating you.
What you should do is take some time and get safety for yourself. This person violated a boundary in your relationship, which is not okay. He then reached out to you for help with suicidal thoughts - which was okay on his part, but your role then becomes to connect him with the right services, not to take on his crisis as your own. Just because he is having an emotional breakdown does not change the fact that he violated a boundary, lied to you, and hurt you.
It is okay to set boundaries for yourself. If he calls to get you to check on him again, you can tell him that you cannot do that, but you can help him get the help he needs by providing information about hotlines, connecting him to another friend he can talk to, or calling professionals. You can tell him now that you are not able to be his mental health crisis responder, and make recommendations to help him find a support system that can function for him. His emotions are not your fault. His behavior is not your responsibility.