Join Kate and Vanessa

The room Kate and Vanessa were in, was a bigger bedroom, for eight people. I walked up to the door and knocked.
"Come in." It was Kate's voice. I entered the room. There were two other girls in here aswell.
"Hey everyone."
"Hey, John!" They all said, almost in unison.
I sat down at the table, next to Vanessa. Kate was on her bed. "You know, this could be the start of a really great porno", she said.
Everyone looked at her, the room was completely silent.
"Oh come on. I'm right and you know it!" She looked at me. "Too bad for you, this ain't a porno."
"We can make it one." The words just came right out of my mouth and I immediately regretted it. Gladly, the other girls seemed to not be shocked, they giggled.
"Was that a proposal?", Vanessa asked. We now reached the point where I wasn't sure if I should continue the joke now. This girl might aswell just turn this into something serious.

Luckily we got interrupted in our fooling around. But this didn't make things any better.
"Well, looks like Kate will actually take you up on that one!", Vanessa said. I followed her eyes and looked over to Kate. She took off her top and now stood there in just her bra, her massive tits almost spilling out of it. My dick immediately turned rock solid.
"What? What's going on?" Kate was absolutely oblivious.
"You can't change clothes just like that in front of a guy!", one of the other girls said, quite shocked, like everyone else.
"Oh, no no, it's okay. John is a good friend, right? You can change in front of friends." Then, she suddenly turned bright red. "I mean, it's not like I'm completely naked in front of him."
"Well", Vanessa spoke up. "I bet he wouldn't mind that either." Now it was my turn getting a red face. At this point most of my blood must have been either in my dick or in my face, which was probably the reason why I said what I said in that moment: "No, i wouldn't mind that."
The room was silent again, except for Vanessa laughing histerically and me stuttering something along the lines of "Shit, sorry, I mean no, but yes, ehm, shit...."
I am not sure if I was imagining things but I thought I heard Kate say "Okay...." very quietly, before immediately getting interrupted by the much louder Vanessa: "Oh man, that was just amazing! Kate, why don't you just get dressed again?"
Unfortunately, she did.

We spent the rest of our lunch break talking about other things, then went back to the group room.