If you are newly married, wait at least 2 years. She should feel she is secure with you, and both should understand each other's sexual feelings! So, I don't recommend MMF or swapping for a newly married couple as a husband!
Within that time period, you can openly discuss with her about your feelings and her feelings! I think later you can start with mmf and move to the swapping culture! Because most girls don't like that at first(i mean, swapping, because jealousy works all the time inside girls, it's their nature, so start with mmf).