intrude (up)on (someone or something)
To involve oneself in something in a way that is meddlesome or unwelcome. I really try not to intrude on my kids, even though they think I'm too involved in their lives. I accidentally intruded upon their seminar before it was over, oops. I didn't realize it was three hours long!
intrude (up)on someone or something
to encroach on someone or something or matters that concern only someone or something. (Upon is formal and less commonly used than on.) I didn't mean to intrude upon you. Please don't intrude on our meeting. Please wait outside.