I do feel sorry for Bonnie, she can't move without having to talk about writing for Katy.
She must also harbour a certain amount of resentment too, especially if she feels Katy jacked her 'teenage' theme, but I'm glad she also acknowledges that, without California Gurls, Teenage Dream, Last Friday Night and the rest, she wouldn't even have a chance to release an album. Swings and roundabouts, I guess