Too selfish?

Sienna

So I’ve been friends with this guy from school for a few years now and we talk and text every single day for hours. I’ve liked him for a long time(3 years) and he has too but we were too shy to tell each other our feelings until recently. He asked me out today and I’m extremely happy but there’s one thing. I’m leaving soon. I haven’t told anyone yet but my family has to move all across the globe because of my parents job and we’ll be leaving in 4months or so. Should I go out with him or not? I think it would be a bit selfish to do so but I really want to at the same time. Pls help!