Breaking a Friends Engagement

My friend just got engaged to someone I think he should break up with. All the times I’ve hung out with them, this guy’s given me the creeps. I think he’s weird and not very nice and a total step backwards for him.  I never said anything about it to him when they were just dating. But now that it’s so serious, I feel like I HAVE to do something. How do I bring this up to him? If this goes badly and they have to divorce, I would feel terrible to have just stood by and let it happen.

Dating in Secret

I’m a lesbian who having an affair with a married woman. She says she loves her husband as a friend but she’s never been really attracted to him. We’ve only been involved a short amount of time and she’s only ever been known as a heterosexual, so she’s not ready to throw everything away for me yet. And that’s fine with me too: I don’t need a serious relationship now either. But I do want to keep seeing her and I want to keep it quiet. I know you don’t approve of deceit, but you have to have some knowledge about dating in secret. What do I do and not do to keep this under wraps until we have a solid plan about what we want?