Ex boyfriend & current boyfriend

so , i was dating this guy for the longest time and he was my first love but he got deployed to Korea and we kinda fell apart soo i moved on to this new guy and we’ve been dating for a good month

Well my ex boyfriend got back from Korea and he’s trying everything he can to get back together with me and I’m not gonna lie i miss his to death but i dont wanna hurt my new boyfriend and i also don’t wanna hurt my ex

He wants me to choose and honestly it’s the hardest thing ever ...

WHAT DO I DO ?