does it still count as cheating?

so im seeing this guy key word being "seeing" and iv sugested several times that i would like to make it official.
but theres a guy another guy who i traveled with last year and nothign happend between us because i had a boyfriend at the time but everyone could tell there was sparks. now i have the oppurtunity to see wat could happen with this him.

but i really like the guy im seeing but am really curious about this other guy. does it count as cheating if i fool around with the other guy?