You're wearing pa- uhm. [He's trying his hardest not to ask "can I see?" because he doesn't need to give Hisoka another reason to call him a pervert. The result is that his eyes widen as he concentrates his hardest on not imagining it.]
[It fails spectacularly.] Why didn't you just say so?
[Action] <33333!!
[It fails spectacularly.] Why didn't you just say so?