That's very funny...and sad. If I read your atty correctly, that is not going to end well for your H. The absolute best thing for you is to totally say nothing nor give any indication your L told you that. Let it play out by your L. Timing will be important to bring everything to a quick end, and if your H gets an idea he can't win using this "bomb" he'll try something else. If your L is able to use this as one more lever to end this quickly, I strongly suggest you stay out of the way and let him.
FWIW, my situation had some similar actions and drama like that. She totally thought she had me over a barrel and it was the "aha!" moment she could use so that everyone thought she just "had to leave him. See, look at what he did!" I have no idea if others believe it or not; nor do I care. But I did care at the time. I do remember that
<shakes head>
AJ
"Our lives begin to end the day we become silent about things that matter" MLK Put the glass down... "Yesterday I was clever so I wanted to change the world Today I am wise, so I am changing myself."