In the manga when the Quinx and Sasaki crossdressed for a mission Mutsuki gets drunk and acts all happy and exuberant. How about an extension to this scene where Mutsuki, after saluting Sasaki, gets a little handsy with Sasaki and flirts with his beloved sensei, not entirely because of the alcohol. And Sasaki likes the attention Mutsuki pays him.

“Shashaki.” Mutsuki rubs his mentor’s shoulders. “You’re sho pretty. You’re the prettiesht girl here.”

“Mucchy?” Saiko raises her eyebrows.

“Sho pretty. Isn’t she?” Mutsuki leans against Sasaki.

“Yas.” Shirazu raises his glass. “A toast to our pretty Sasaki!” 

The Quinx clink their glasses together, and Mutsuki turns back to Sasaki.

“You’re the nicesht pershon I know. Do you like me? Am I your friend?” Mutsuki grips Sasaki’s arm to keep his balance as the room spins around him. “Pleash shay yesh.”

“Of c-c-course, you’re my friend.” Sasaki’s face is purple. But Mutsuki’s eyes are so round and cute and innocent and irresistible. 

“Yay!” Mutsuki laughs.

Sasaki leans over and hugs Mutsuki. “See?”

Mutsuki has tears in his eyes. “He likesh me.”