horn in on (something)

horn in on (something)

To join something when one is unwelcome; to intrude or encroach. Ugh, my little brother keeps horning in on all the things I try to do with my friends.
See also: horn, on

horn in on

Intrude, join without being invited. For example, She has a rude way of horning in on our conversations. This expression alludes to an ox or bull pushing in with its horns. [c. 1900]
See also: horn, on