I am looking for a specific fic in which Jensen and Dean are twins and so are Misha and Cas.  If I remember right, Dean and Cas were together first and there was some kind of family event (I think it might have been a funeral) during which Jensen and Misha meet.  I do remember that Jensen was very shy (and maybe a virgin...?) and Misha was afraid of staying in one place.

If someone could please help me find this fic, I would greatly appreciate it. :)