OW does not care about a trifling thing like someone else's marriage! I told my H one day he needed to thank me, because my "blackmailing" probably saved his behind. I told him NO SANE WOMAN with any kind of self worth dates a married man. I said I wouldn't touch one with a ten-foot pole. What if he is lying? To which H helpfully replied that he was accused of that. Blech!
On the other hand, I'm wondering WTF your H is doing showing you videos like that of his OW? Not very honorable, for sure. Keeping you on his side for cake-eating? I'm not sure, but warning signals flared when I read that bit. Be careful, please.