I want just a little credit for not taking my friend's girlfriend up on it
What did you not take her up on?
It would be way too complicated.
You made the right decision, you shouldn't be with a cheater. Find you a wholesome girl instead.
My friend doesn't deserve her.
Even if you think your friend does not deserve her, it is great that you did not participate in cheating. Your friend would have been heartbroken, and you would have just made yourself and her a cheater. The better thing to do would be to tell her to talk to your friend and figure out what the issue is in their own relationship.