Breaking Up to Save Your Sanity

So I was watching the season finale of Keeping Up with the Kardashians the other night. Kourtney was trying to decide if she should break up with her longtime boyfriend, Scott, because his shady actions in the past always made her feel like she couldn't trust him. Khloe also found out that her boyfriend, Rashaad, had been cheating on her. While Khloe kicked that man to the curb immediately, Kourtney struggled over whether she was ready to end her relationship or not.

I don't know about you guys, but I know how Kourtney feels to be conflicted in her situation. Sometimes you love somebody so much that you either become blind to all of their weaknesses or it overcomes you so much that you can't imagine living without them despite the way they can sometimes hurt you. 

I'm a believer in love over pride. I feel like I can learn to get over minor differences or mistakes if I really love somebody as long as they're willing to acknowledge it and try their best to work with me. But how do you know when all those little things are too much? Say if you were with somebody that just irritated you constantly with their little mannerisms and habits, but when they weren't irritating you made you the happiest you've ever been? Do you bear all the times when you feel like knocking them to the moon if it feels so right the rest of the time? How many chances should somebody get until you just give up on it altogether? Is there a limit to how many things about a person bother you to be able to stay in a lasting relationship with them? What if they have significant faults? I have no idea. I am so bad at drawing the line in relationships because I'm always trying to give them a chance and make it work.

Anybody have a good rule for this?