My wife came home full of cum..

Does it turn you on that she cheated?

if it does embrace it, tell her you know and ask her to tell you the details while you lick her out. Show her how horny it makes you. Comfort her and let her know your not upset

if it doesn’t turn you on, then speak to her, tell her you rather do a mmf so you can see the pleasure she gets. If that’s what you want. Find out why she cheated, fix what’s missing in your sex life.

If cheating or or sharing isn’t your thing, why are you here?
Decide if you want to live the rest of your life with her, knowing she cheated and will likely cheat again.