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general::
Phrase(s): horn in (on someone)
Fig. to attempt to displace someone; to interfere with someone, especially with someone’s romantic interests. • I’m going to ask Sally to the party. Don’t you dare try to horn in on me! • I wouldn’t think of horning in., Phrase(s): horn in (on something)
Fig. to attempt to participate in something without invitation or consent. • Are you trying to horn in on my conversation with Sally? • I hope you are not trying to horn in on our party.
McGrawhill's American Idioms And Phrasal Verbs