Well it’s wrong and is he aware that your married?
I know it is difficult to completely stop yourself from having feelings for someone else because feelings tend to develop organically, it's difficult to have conscious control over it.
But make sure the conversation you people have is friendly, because of your marital status, it can take a toll on your marital relationship and you definitely don't want that.
Do you think you can set a boundary for your relationship with your coworker?
i dnt knw about his feelings
he knws m married
Try to know indirectly what he feels. also, can you set a boundary for yourself?