A game

Konoka stands quietly and slinks over to where Negi and Setsuna are rapidly approaching making-out. She giggles to herself as she smacks Setsuna's ass.

Setsuna: gasp! Negi-sensei!

Negi: Hm?

Setsuna: I...! Ojou-sama told me to kiss you, but nothing more! Please, control yourself.

Negi: Eh!?

They resumed kissing (on their own choice), giving Konoka a chance to quickly cup Negi's crotch. This time he gasped and pulled back.

Negi: Setsuna, what are you doing? I thought we were keeping hands to ourselves.

Setsuna: We are. I am.

They went back to kissing, but just before their lips met again, Setsuna whispered 'keep your eyes open' to Negi. He did, while Setsuna closed her's. Konoka had her hand (or more accurately her fingertips) only an inch from Setsuna's panties when she threw her eyes open and caught her.

Konoka: EEK!

Setsuna: Ojou-sama!! What are you doing!?

Konoka: Whoops! You caught me, Set-chan! You know what that means!

Setsuna, blushing but smiling: R-right now? With Negi-sensei here?

Konoka nodded, so Setsuna let go of Negi and stepped back.

Negi: I don't understand, what are you two tMMF!

While his mind tried to solve the riddle, Konoka had stood and taken her friend's place at Negi's lips. And tongue was definitely her preference. Negi's eyes were again wide open, but soon closed again. Until someone patted his ass.

Negi: Konoka! You too!?

Konoka, giggling: This is the game, Negi-kun! If you catch the person about to touch you or the other girl, then you switch places. Fun, huh!?

Negi: WHAT!?

Setsuna: It's simple, Kono-chan was caught trying to pull away my panties, so now i am to try to do things like that to you two before i'm caught.

Negi: You do this...often?

Setsuna: N-not 'often'...

Konoka: Every night after class!

Setsuna: KONO-CHAN! Please learn how to keep a secret!

Konoka: Why? Now that Negi-kun's in, we might as well tell him everything, right? Like they say in Negi-kun's country, 'in for an egg, in for the count!'

Negi: That's not quite it...I think you mean 'in for a penny, in for a pound'.

Konoka: Hee-hee. A 'pound', you say? Naughty-Negi-kun!