I think I have a crush on an older co-worker...who's married
Does your co-worker know you are attracted to him?
I am not sure.
Do not make any advances towards him. He is already in a relationship, plus you are coworkers.
I agree and I will stop talking to him.
You don't have to stop talking to him outright, just make sure the relationship stays professional only. It would be hard to do a job without coworker collaboration.