He says the first thing that crosses his mind

"It's dirty!"

It was the first thing that popped into his head. Thinking thoughts like that about Katie was dirty! A complete betrayal. He could absolutely not entertain thoughts of betraying her trust like that. Allowing her to take his penis into her mouth or pussy without knowing that it was really him was ****, right? He was an awful person to even contemplate...

"What do you mean it's dirty? You mean you... oh! Oh geeze... gross..." Katie suddenly held her hands away from herself in distaste.

Andrew froze. Had he really said that out loud?

"S-sorry!" Katie suddenly squeaked out, still holding her hands up like they're unclean. "It's not that uh... you're gross, or anything. It's fine y-you know, experimenting is g-good!"

What did she mean by experimenting, he wondered?

"I mean, I... I think it's great that you're giving it a try? So many guys are so... weird and insecure about it. I think it says great things about you that you're willing to have an open mind and not dismiss it out of hand. Though, speaking of hands, I'm gonna go wash mine quick..."

Andrew blushed bright red, though only slightly more brightly than Katie was turning as she scurried off to the restroom. He cursed mentally. There was only really one way to take 'It's dirty' in context. He had basically just admitted to putting a dildo up his ass to his oldest friend. There was no way he would be able to ever look her in the eyes again.

Andrew quickly dropped his penis in the drawer and slammed it shut. He didn't want to be anywhere near it after having it implied that he was doing that sort of thing with it. Flopping down into his desk chair he developed a thousand yard stare at the wall, wallowing in his mortification.

A shadow falling across his desk finally broke him free of his daze. Katie was back from the restroom already.

"You alright Andrew? I get why you were being cagey about it earlier." Katie smiled at him warmly, with her cheeks still glowing with the rosy hue of embarrassment. "You don't have to worry about me blabbing about this to anyone, okay? It'll be our secret as long as you want it to be. If you ever want to talk about it, I'm here for you."