All the sudden, he loved me again. He got laid and all was right in the world for him.
God, this is difficult for me, to say this, because I almost did what your idiot husband did. But the light switch moment came before I actually had sex with the OW.
His thoughts might have been: "Hey! I got laid! Oh, ****! I didn't get just laid! I just betrayed my wife! I betrayed the woman I love!"
Realising that you too, can be a cheating POS can come as a shock. Unless all you were looking for was sex with other people, but that's only one potential reason why people cheat.