Ask her if she's happy
and explain that it wouldn't suit you, but if she's happy with it then that's enough.

Hopefully that should make it clear to her that you're there for her to pick up the pieces, should that arise.

There isn't really any more that you can do - I've seen friends of mine in terrible relationships - most of them eventually regain their senses. Those who don't - and I've one close friend who is married to a man I find quite unpleasant, I don't think she's happy but she says she is so there isn't any more that I can do....She knows I'm there for her whatever.
( chickenlady b3ta's very own Elizabeth Taylor, Mon 3 Nov 2008, 21:46, Reply)