why do toi think that damon say that elena doesn't deserve him ??

Because he does (to an extent) l’amour his brother and wishes him no ill..... Okay maybe the no ill part isn't true but the rest could be.

Because Damon does not deserve Elena yet. Well, before that whole scene (which essentially proves that he is now worthy of her). He killed her brother. He's got a lot of work to do before she'll forgive him, let alone l’amour HIM. It's just the beginning though :)...Delena FTW.

IM TEAM DAMON,but it's because Damon has killed to many people, hurt her in the past and only shown interest in his hapiness. After his brother apologized, he realized how good he is and knew that the good brother should get the girl, he thought it was selfish to say it because he knew that he shouldn't bring up those feelings with his brother's girlfriend and that for all he knew, she could feel differently towards him after and that would be stealing her from the bother that he thinks is better for her.