Dekiai Rule
From Attractive Fascinante:
Miyashita sensei was always an overachiever, but his perfect life was disrupted when he met his desired-filled student, Jindou. Trying his best to keep Jindou back on track, sensei had to guide Jindou personally as well as to fend off his ex-partners. Love developed as time went by, but sensei kept a distance from Jindou by trying his best to maintain an innocent relationship between them. Would Jindou succeed in breaking down sensei’s territory?