We had a 3some when we were in London a couple years ago. She talked me into it.
Holy CRAP! That's too much information!
I'm just kidding .
It doesn't have to ruin your marriage and it doesn't change your method of operation either.
Follow the DB prinicples, work on yourself and your own shortcomings/oversights within the marriage, get a life and let your wife sort this out for herself. Don't put pressure on her and don't make her feel bad. Trust me, she already does.
.