Absolutely nothing. The word "crazy" floats around women like dough being tossed in the air at a pizza restaurant. It happens far too often, and it's rather unnecessary. To throw a girl under the bus and slap a label on her that says "crazy" is the equivalent to a guy being slapped with the label "bad in bed." It's a stigma that causes guys to want to stay away from a girl that got called crazy, and girls to stay away from guys that don't realize that it's about the motion of the ocean.
No girl wants a guy that's bad in bed, just like no guy wants a girl that they think is "crazy."
But here's the actual truth on that: girls literally aren't crazy or asking too much of you. They're just asking something that you're incapable of. You're flat out just not their cup of tea. You don't like the constant attention and affection and that's fine. You don't need to go off and call her crazy for it.
It's unnecessary and actually a really harmful way to disband from her.
Instead of calling a girl crazy to your friends, you should actually try and assess your situation with her. Why did you not like her? Stay away from just taking the easy way out, you lazy pile, and just saying, "Because she was crazy!" because we all know you're full of it, and you just couldn't handle what she was willing to put out, and you're more than willing to loosen the blame on your end and place it on her to add to her anxiety level for the next guy she tries dating.
This isn't me being full on feminist by any means. Most of the times when people break up that involves the guy calling the girl crazy like it's a nonchalant thing they do during their everyday life; it's more than likely always his fault for getting into a relationship he clearly wasn't ready for.
Most women, when getting into a relationship, are more reserved than men. Guys are more than likely to be the eager beavers immediately when trying to get the girls attention which leads to the girl finally tearing down her walls for that guy. Once she's torn down her walls, the guy will more than likely knock himself out of the honeymoon phase quicker than the girl. Women are more likely to have an elongated honeymoon phase due to the nature of their past relationships either constantly being a mess or ending in a rather horrific fashion.
Just because a guy comes out of the honeymoon phase too quickly, and doesn't want his phone blowing up like he used to do to her, doesn't mean that she's the crazy one. Why is falling for you and caring so much to the point where you're all she thinks about so crazy? Why do guys consider a girl crazy if she wants to spend so much time with them and so much effort on them? Most guys have absolutely no valid answer. Mainly because of the simple fact that they struggle to deter between lust and love during the beginning phases of a relationship.
If a guy takes a long time to even consider full-on officially dating a girl, then breaks it off unexpectedly or savagely puts a girl down into the friend-zone level, she has the absolute right to be flat out pissed off for putting in all the effort and time into trying to do things right and to finally get him to want to be exclusive with her. Now, don't go and key his car or anything like that because retaliation rumors are considerably awful to deal with.
Girls get the short end of the stick when it comes to anything romantic. Society constantly lays the pressure on them to wait for the guy to ask them. That leaves them hanging in the balance waiting and eloquently doing everything they can in order to get a guy to fully invest in them. Doing this repeatedly over and over with every new guy that comes along is probably the most exhausting thing imaginable.
So, don't consider them crazy for getting upset with your dumb decisions to ignore them for the smallest most ridiculous reasons. "She had a weird laugh, turned out to be a crazy chick." She has a unique laugh, and you made her upset and she reacted accordingly because that's a stupid reason to not want to continue on to the next phase of a relationship with her.
Being honest with a girl if you're going to break up with her and then being honest with the people that ask about the situation is something that should be highly valued.
If you find one little thing to not fit with what you want and you're more than willing to break it off for that one reason, maybe you weren't ready for a relationship after all and you should be honest with her about that. She's more than likely going to be saddened, but it's nothing that's going to leave her hanging to the point where she's going to get upset with you and do anything you'd consider "crazy." Then you can simply tell your friends: "I am immature, I led her on, and am 100% not ready for a relationship, so I broke it off." They'll get the true picture, and nobody gets the wrong idea about anybody.