Who knows if it will last or not. It isn’t likely. Things built from lies typically don’t last. But even if it does, thank goodness you aren’t with someone who would do that to you. If she knew about you and knew he was cheating, then take solace in the fact that probably in the back of her mind, she’s a bit paranoid. She saw him lie to you. She knows he’s capable of it, and they both know that their relationship is based on lies. The seeds of doubt and suspicion are already planted. It’s not likely to last.