I've come across a few fics that have Gregor try to come to grips with the sexual trauma left behind by Cavilo, though it's not all that frequent. (I admit that the topic might've been Done To Death in the LJ fic era, but I wasn't around for that bit.)

Actually, now I'd be kind of interested in seeing how Gregor's Serg-related paranoias and Cavilo-inflicted traumas interact. Did Cavilo enjoy it rough, or perhaps spot a weak spot and then sink in her prongs?