51 phone calls from the same number and your husband doesn't know who/what they are? No matter what these numbers are, you are certainly no over-reacting and if your husband is not taking your concern seriously, that raises a second red-flag to me.

Suppose you give him the benefit of the doubt. I think that a change of number is in order. After all..51 times is a LOT of unexplainable calls from the same number. They're eating up your minutes!!!

I would not give the benefit of the doubt here, but I am not in your situation. Sometimes I feel a bit jaded when it comes to the "looks like a duck, quacks like a duck".

Since you're going to talk to Penny about it, maybe you COULD just put in on the backburner until then. If your husband is telling the truth, you're not going to get anywhere with him anyway..no explanation is going to satisfy you. If he's not telling the truth, he's not going to now.

I'm glad you have Penny to talk and guide you.