When you absolutely, without a doubt, are certainly sure, that a dear friend is making a huge, life-altering mistake, what do you do?
1. Voice concern but stand by their decision and make yourself available to help pick up the pieces, all the while knowing they're making a horrible decision
2. Voice your opinion loud and clear, refuse to watch them ruin their life, thereby turing your back on the situation and running the risk of losing the friendship
It's a damned if you do/damned if you don't situation, folks. We've all been there. I'm usually a #1 person but this one might call for the latter.
What type are you and how has it worked out for you in the past?