Do you know for a fact that she is nuts, or is this what he is telling you? Why doesn't she know about the two of you yet? Is she really nuts or is he still sleeping with her? If he isn't sleeping with her, why does he feel the need to keep the relationship from her? However, if he isn't having any type of relatioship with her, then no I would not end it simply because she doesn't want to see him with someone else!