At some point during the poly route with Kol and Nasir, Nasir asks Yoshi if he even wants to sleep with Kol. The gallery's very last CG illustrates what happens if Kol doesn't like Yoshi's answer :D
Yup, this is correct. Choose the Kol route, but avoid any kind of romantic contact with him. When Nasir confronts you in the galley, you'll get three choices.