Don't say anything about ending your relationship. If you are getting stale on your sex life, take time to be together, talk to each other. Reminisce about your young love. Go on a vacation. Maybe it will be just an overnight stay at a motel, but don't let your work bog you down.
Companionship is important for a healthy marriage.
Don't look back and pick up the negative. Begin today to add sweetness in your married life. One woman told me her husband had a girlfriend. She said she could not forgive him. I asked her if he had girlfriends before they became engaged.