Narrated Ibn Abbas (RA) : 

I have not seen a thing resembling lamam (minor sins) than what Abu Hurairah (RA) narrated from the Prophet ﷺ who said "Allah has written for Adams son his share of adultery which he commits inevitably. The adultery of the eyes is the sight (to gaze at a forbidden thing), the adultery of the tongue is the talk, and the inner self wishes and desires and the private parts testify all this or deny it."

(Hadith # 6243:Sahih Bukhari)