<human>: We went on a first date that ended turning into a one night stand... something I've never done before. I was thinking about him again last week for some reason unknown to me, and I threw his name into google and his linkedin popped up! So I was perusing and a day later I had a linked in request from him and a message saying hey, and that he had lost my number and it was really good to say hi! All this unsolicited 8 months later.
The problem is that we met while we were in London. He was visiting family, and I live here [London] for University. He's now on the West Coast, USA, and I'm moving back to the East Coast USA come July.

Good news is that I'm working for my family business, so I will be travelling out to the West Coast for business, as well as the UK. We exchanged 4-5 messages on linked in, and I asked him to add me on facebook and I've not heard anything since.

Do I go ahead and add him? I have no idea what he and I would be, but at the very least I'd like to keep a line of friendship because I found him very interesting and genuinely relatable. He seems like a fun guy with a good head on his shoulders so I would like to keep up contact in the least stalker/creepy/overly-attached-ONS way possible. Haha, how does one deal with such things?
Any and all advice welcome of every shape and size welcome! Help? Advice?
22/f 25/m Relationship: 1 Night

Summarize the given text in a few sentences.
<bot>: Thinking about my ONS 8 months later, find his linkedin, he adds me the next day with a message. Exchange some messages, thinking about adding him on facebook, unsure of how to navigate without being creepy?