Skip to main content
to step out on someone

to step out on someone

9.5
To have sex or a romantic relationship with someone who is not your partner
  • phrasal verb
  • NSFW
translation icon : serle infiel a alguien
  • After years of trust, she felt betrayed when she learned he was stepping out on her.

Examples

  • He found out that she was stepping out on him with his best friend.

  • They broke up because he was stepping out on her with multiple partners.

  • Her asshole boyfriend's stepping out on her.

Synonyms

to step out on
vsto step out on someone
  • NSFW
5 8.7

To have sex with someone else while you have a partner

is identical in meaning but adds an explicit named partner

Antonyms

faithful
  • NSFW
120 2.1

Having sex only with your husband, wife, or partner

How Unfaithful

to cheat on
  • NSFW
323 3.3
to step out on someone
  • NSFW
9.5
to flirt
267 3.1

Surface Forms

step out on someone infinitive
stepped out on someone past participle
stepping out on someone present participle
steps out on someone third person singular

Morphology

step + out + on + someone

The literal constituents ('step' + 'out' + 'on' + 'someone') do not directly yield 'be unfaithful'; while 'step out' can suggest going out with others, the specific sense of secret romantic/sexual involvement is idiomatic. There is a partial, metaphorical link to 'going out' but the unfaithfulness meaning is not fully predictable for a B1 learner without prior exposure.

Etymology

Step out on someone comes from the image of leaving your partner to step out with another person. One popular story says people used step out to mean going out on a secret date, so step out on someone came to mean 'to be unfaithful'.