Because Fonzie had never removed Starslip’s mask

"There's still something you haven't taken from me," Starslip pointed out. "And I'm not talking perverted shit like shoving that thing in my holes."

The Bewitching Mob Boss blinked, clearly confused. The Violaceous Victor watched on as the brunette looked deep into her eyes, as if she were looking for some kind of clue. Finally, it seemed as though she’d found it, realizing what Cassie had meant: Her mask. She was still wearing it. At no point during either of their encounters had it been taken off. Fonzie had seen the blonde completely naked and exposed, save for her face, because once that was gone, that would be the end of all secrets and aliases between them.

Whoa, maybe I should think about that a bit more, Starslip began to wonder. I was gonna taunt her some more, but if she calls my bluff, then that’s it. My secret identity is blown. Even if she never tells anyone else, my worst nemesis EVER would know who I really am. Am I really ready for that?