CONFUSING COWORKER

A little background story: I'm 20, and I'm a fitness coach. Long story short, everyone I work with is fit, funny, and hot. So. One of my coworkers and I have always gotten along (even before I was coaching and was just a client) but it was always a platonic connection. Almost like siblings too. Recently, we've been flirting alllll time time. Some jokingly and other times seriously. HERES THE FUCKING CATCH. He's 31(2?). Now, age doesn't bother me as last year I dated a 27 year old (don't judge). But the fact that he's my coworker, older than me, and I'm moving away in less than a month has my brain fried. He asked me out for drinks soon since I took care of his after shift duties the other days and has been super flirty about it. IDK WHAT HELP IM ASKING FOR I JUST NEED SOME NONBIASED OPINIONS AND ADVICE SO LEGGO 

Sorry for the novel 😂