I love your "predator" reference. Back when I was still making the mistake of attacking OM, I'd often refer to him as a "predator" or "home invader".
Men and women that would knowingly get involved with a married woman or man, and prey upon their emotional weaknesses, ARE predators!! In every sense of the word.
I detest them. Do not "make friends" with them, do not expect them to deal honorably with you (for they are, by definition, DIShonorable) and do NOT take what they tell you as TRUTH!