June 6th, 2012 at 02:33am
I think that it's dangerous, especially considering that he used to cut himself before, and was plenty suicidal. I understand why you'd be worried.
His relationship with this girl - the 'I'll cut if you cut' thing - will only make it worse for him. What if she never stops cutting? What if, in cutting again for that girl, he exposes himself to the chances that he might actually self harm for other reasons as well?
You could tell him to try things other than cutting to get his friend to stop.
If he does want to stop doing it then the best thing you can do is be supportive, and if this situation arises again whatever you do don't let him think you're disappointed in him or that's he's let you down because he'll feel guilty which is more likely to make him do it again - however strange that sounds.
And I agree that you should encourage him to find another way to help his friend.