Was it just a kiss? am I a rebound?

ive like a guy at work for several months now, when I started at the work place he took me out lead me to believe he was single with all the flirty texts, outings and compliments only to turn out he has a gf. Last week we went out and he tells me he and his gf broke up, that night we kissed and was all very cosy. It hasnt been mentioned at work since, just hellos and smiles :( Was it just a kiss? really like this guy.