the scar on her shoulder

Does anyone know where that scar on her shoulder is from cause he seemed to freeze up/ notice something In the first few chapters.

Also that other rich boy whom she dumped, I find it weird that that rich boy's friend (sex? friend) said that that girl is the only one he dates seriously (probably cause he didn't eat her), so frankly my guess is she knew them when they were young (met by chance or childhood friends {unlikely}) and she got hurt either protecting one of them, playing, or an unfortunate event she was involved in due these boys.

Or she is an important key in obtaining power over the other boy, whether emotional triumph or (I guess) political power gain.

Its just the boy she dated was a womanizer but he didn't touch her, and the guy she met in the bar to have revenge on her boyfriend (I think) saw her scar after undressing her (yah to have his fun) and his interest peaked. But since he was interrupted and she escaped, what would his reason be for looking for her (not personally) and why did her ex not touch her

also with this resent update where he mentions that since no one has touched her she avoided punishment. I mean these guys don't really care if they kill people, so... why isn't she being torchered or left for dead...there's got to be something big going on... >.< (⊙…⊙ )