I like a guy at work but dated someone else there before. First guy was jealous of second even though me and second guy never went out. He said we looked at each other flirty. I would really like to get to know second guy better but he knows first was jealous of him. Do you think me and second could work out and if so how do I go about letting him know I want to get to know him better without coming on too strong?

This had the potential for a messy situation. Workplace dating can be sloppy.
I'm assuming you are both adults, just tell him you'd like to get to know him better and see where it goes.