keeping in contact with a fling?

[Alessa]

I've been having this fling with a really cute guy. He's really sweet, loves to cuddle with me and we have nice conversations when I'm over there. Clearly we spend a lot of time in bed, but we also watch movies and tv together at his place. I admit I'm falling for him, but I wouldn't mind just being friend with him. We're both moving away very soon (he might come back in a few months), but I want to keep in contact with him. How should I approach this subject with him? (I'm in my early twenties, he's in his late twenties)