butt in
To interrupt someone or something. I'm sorry to butt in, but I have some information that might help. Mom is always using the phone in her office to butt in on my conversations!
butt in (on someone or something)
to interrupt someone or something. Pardon me for butting in on your conversation, but this is important. John butted in on Tom and Jane to tell them that the mail had come.
butt in
Interfere, interrupt, intrude. For example, Mom is always butting in on our conversations, or It's against the law for employers to butt in on personal matters. This term alludes to the thrusting of an animal with its horns. [Slang; 1890s]
butt in
v. To intrude upon or interrupt someone or something: You're always butting in my conversations, and I wish you'd stop. I can't believe that you butted in on that meeting! We were having a good talk until you butt in.