OK, no pictures, but my Sim in university was driving to The Grotto to hang out after class. She starting driving toward it when I noticed fairy wings clipping outside of her car. She had a passanger, but I clicked visit, instead of visit with. I guess since they where going the same way, the fairy decided to jump in. All cool by me, just sort of odd as in the years I've played The Sims 3, Sims only went along if i selected them to.
Edit: They're roommates, so maybe that's why.