You're a handsome couple—thanks for enclosing the lovely picture (sometimes it's nice to see the face of the person I'm responding to!
After trying some new arrangements—only together, only at sex parties, DADT—he realized he wasn't comfortable with any situation.
He told our therapist that every time I hooked up with someone, he was retraumatized because it reminded him of the time I broke up with him for six months 20 years ago.
Or maybe you're the wrong kind of sadist: the un-self-aware emotional sadist.
You say you love your wife, but you also say she'd be crushed—destroyed—if she discovered what you've been doing.
Which means it's both ultimatum and bluff-calling time.