To intrude into or interfere with someone else's affairs when such behavior is unwanted or unsolicited. My mom is always nosing in on my love life.Make sure no word of this gets out. The last thing we need is to have the police nosing in on us.
nose in on
v.
To listen in on or get involved in something where one's presence is not wanted: You're always nosing in on my conversations, and I wish you'd stop.