Dictionary.com
Thesaurus.com

cheat on

Idioms  
  1. Be sexually unfaithful to, as in They broke up right after she found he was cheating on her. [Colloquial; 1920s]


Example Sentences

Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.

Clear-eyed hindsight shows that Sullivan didn’t deliberately cheat on her boyfriend, though.

From Salon

In “Holiday Party,” she recounts a recurring dream in which Koma cheats on her with her friends.

From Los Angeles Times

“And three months ago I made the biggest mistake of my life and cheated on her.”

From Los Angeles Times

Jenni told Shannon that Swan cheated on her frequently, and he had a condition which meant he would do things in his sleep that he was unaware of.

From BBC

Ninety-six people were prosecuted for attempting to cheat on driving tests or impersonate candidates in the 12 months to September last year.

From BBC