Being used to Dexter's dick helps to explain why she isn't more bothered than she is about Anon's, but I don't want her to actually be into small dicks, because that messes up the story where she likes him for the way he treats her instead of his body; she's the fulfillment of Tina's promise that women worth having will be able to overlook his size if he makes himself desirable in other ways. I'm totally for having a character who likes smaller dicks, but it can't be Roxxy. She's the popular girl, and it has to be hard for Anon to win her over.
I'm totally down with her unintentionally embarrassing him in public, if I can find an opportunity for her to do it! It would make sense for her to speak lovingly about his deficiencies once their relationship is established. She can grow to like it, but she can't already like it before they have sex. She told Jenny that sex with Dexter wasn't good because of his size. She'll learn that it's possible to enjoy sex with Anon despite his size.