Actually I would give the save advice. There are people in this world that don’t cheat if given the opportunity to. They are able to actually have friends of the opposite sex and keep it just as friends. There hasn’t been anything hidden, she has access to his phone.Glad to see you're not gonna take the insult. As they say, take what you need and leave the rest. Emotional cheating is cheating! And just read Shirley Glass' book, "Not Just Friends" (and also the many numerous posts on this and other infidelity forums) to see how this scenario (loose and innapropriate boundaries with coworkers of the opposite sex) plays out on all too many occasions.
If you reversed this situation and it was your husband here making this exact same post, about you, in the exact same scenario with a younger male coworker, I highly doubt he'd be being told he was "jealous" and "insecure"! Good grief!
There are females on here that actually argued my point of view when the situation was between a wife and young man. He was call controlling and insecure.