He Wants a Threesome – Should I Do It?

My man & I have been together for about five years.  He just recently told me that he wants to bring another woman in the bedroom.  I’m not saying that I am totally against it, but I’m also not saying that I am 100% down with it.

I’m curious to know why all of a sudden he wants to have a threesome out of nowhere.  Is he bored with me?  Does he just want to spark things up?  Does he even really care about me?

If I do decide to do this, I fear that our relationship will never be the same.  We had some issues with him cheating a few years ago one time.  I haven’t heard about him or even suspected him of doing anything else, but I don’t want him doubling back to the person we may have a threesome with.

I need your advice.  Is it okay to have a threesome with your man?  Would you advise it?  & if I do agree to this, do we find a girl that we already know or don’t know?  &  last question, would I be a fool if I set ground rules for the threesome?