Holy emotional affair, Batman

Either you are a really bad cook and she is a really good one (and even then, he shouldn’t be accepting her lunches, it doesn’t send the right message) or he is interested in her. Does she even know he is married?

He should set up a meeting. If you can't also be friends with her then she should stop

if she's old, she may be just a sweet lady. if she's young, then Aw Hell No!

Well, you wouldn't want your husband to have an affair with a mean lady, would you?

he is emotionally cheating on you with his work wife. at least I hope that's all it is. it's rude and he needs to tell her to stop. they have both overstepped their boundaries

I doubt he'll get her to stop of his own accord. Time to lay down the law and set some boundaries.