I‘m sorry- if he is 31 fucking 19 year olds there is something wrong with him. When I was 19-20 i dated someone who’ was 29 and way more experienced (career,life, etc) than me. At the Time i thought it was cool dating someone with so much life experience and i looked up to him a lot. Now I’m 23 dating another 23 year old and I think- what the fuck? It’s fucking disgusting. I feel like he either thought he wasn’t good enough for other 29 year olds or wanted to seem superior to someone 10 years younger than him. I can’t imagine that range again. I’m sorry you’re going through this but take it as, you’re better off without him.