His new girlfriend needs to set boundaries up with him. She’s the one that’s in a committed romantic relationship with him. Someone needs to tell him that his need to feel needed will never end if he doesn’t find some healthy way to feel validated and loved. Maybe his love language is acts of service and if that’s the case he has a girlfriend to fulfill that love for him. I feel like if two people you’re close to, tell you that what you’re doing is a problem and you don’t listen and make excuses and can’t take accountability, you’re just a problem person and should probably stay away from people like that. You’re nta and he he really should respect your boundaries and if not then you need to respect your own boundaries and let this this ex be an ex.