She's gonna turn him into calamari.

...wait a second, was Headphone-chan about to take her shirt off? she's holding the bottom of her shirt...

Why isn't she wearing any panties?
I guess she's regretting not doing it now.

Liggliluff said:

Why isn't she wearing any panties?
I guess she's regretting not doing it now.

She was wearing them you can see them slightly in the waist part of the trousers. Also, in the manga, goggles has pantsed multiple people multiple times and every time he does he also takes down the underwear as shown in the picture.