Minerva "Minnie" Mouse is a famous Disney cartoon character, recognized as being the wife and/or girlfriend of Mickey Mouse.
In "A Picture's Worth $1000", Walt Disney draws her naked, using the real Minnie Mouse as a character model. Minnie Mouse is highly uncomfortable and embarrassed with having to expose herself but Disney demands she continue stripping for him anyway.
In "Peter's Daughter", Brian and Stewie went to a crappy old beaten up house, where they could heard the mice having sex in the walls. The voices of Mickey and Minnie Mouse were heard, moaning offscreen.