If it is MLC they affair down. This is because of deeply felt inadequacy - they find someone they feel 'better' than, and to whom they will be a white knight. Because they feel inadequate the person they find will surprise us and most of the people who know them.
I realise we would say that they affair down, but I think most of us are sane enough to know when it is a relationship of 'equals' even if we do not like the person.
Doesn't mean the affair will end quickly though: sometimes they stay with OP for a long time
