Is my friend emotionally cheating, or is this coworker just a friend?

First said this guy coworker gave out his number she kept it in the backpack than months later tells me Drea had her number since two months ago and it’s really nothing serious at all he does keep asking her to invite him somewhere to hang out tho she added no but one time she blurted out that maybe one day they will go hiking or something since they both enjoy it… and basically she brings his name up almost at least once if not more a day ohh he gave me candy you want some anyways am I overthinking? (She isn’t happy in her marriage she clarified it more than once)

Is my friend emotionally cheating, or is this coworker just a friend?
Post Opinion