@Xiuzhen,
You don't have time for a cafe get-together before you leave?
I'd say to at least meet him once, briefly, and a cafe date is perfect.
He seems a bit old but you never know. He might become a friend or a boyfriend. There is no way of knowing without a mini-get together.
Afternoon/early evening get-togethers are best as you can make them brief and on neutral ground.