Adrian was right about one thing—his mother was definitely unhinged. Knowing the reasons behind it lent Ivy a bit of sympathy for her but she was still angry about the unfounded accusations leveled at her friend.
Carson did genuinely care about her even after finding out about her secret. If he didn't he wouldn't have allowed her to continue cheating off of him so she didn't fail the twelfth grade or called her to check up on her when he was worried.
Rosa was wrong about his motivations. They were friends. Two misfits that didn't jive well with other people but did with each other. They were kindred spirits despite how different their reasons for not having other friends were.
He cared about her as a person, not as an object. Goodness knows she had heard enough lewd thoughts over the years to be able to distinguish between a creepy guy and a not creepy one.
Carson was one of the good ones. His head was refreshingly clean compared to other boys at their school.