His feelings for Fujitsubo, who enters the kokyu (Empress's residence) of his father because she looks like his lost mother, became stronger and he has a sexual relationship with her (resulting in Emperor Reizei), but no one knows of their illicit affair.
亡母に似ているとして父帝の後宮に入った藤壺を慕い、遂に一線を越えて子（後の冷泉帝）をなすが、密通の事実は世に知られることはなかった。