Ive had some first hand experience on this topic.

I kind of liked her so much that I didn't care about what my friend wanted though.

He would have done the same to me if he had the opportunity.

I left him depressed for a long time and me and the girl broke up....so it was a LOSE/LOSE situation for both of us...

I got my share of depression over that too...

Don't do it man...respect your friend