Ngl, a 3some would ruin the story for me, even if it's only a one time thing. It just doesn't fit in here since Deyeon doesn't have nearly as much of a connection to Yiyoung and Director Kang as Yiyoung and Director Kang have to each other, after everything they've been through together. Also, Yiyoung and Director Kang don't seem to have any interest in Deyeon sexually/romantically so a 3some would be very unfitting imo.
Ngl, a 3some would ruin the story for me, even if it's only a one time thing. It just doesn't fit in here since Deyeon doesn't have nearly as much of a connection to Yiyoung and Director Kang as Yiyoung and Director Kang have to each other, after everything they've been through together. Also, Yiyoung and Director Kang don't seem to have any interest in Deyeon sexually/romantically so a 3some would be very unfitting imo.