does anyone know which episode was it, when dean and lisa met for the first time?

When we saw Lisa the first time was in "The Kids Are Alright" Dean actually met Lisa several years before the episode so it was mais of a reunion for them but a first for us :)

The first time that dean and Lisa first met is the episode the kids are alright episode 2

i think they met ben's birthday party

Changelings

They met way before Ben's birthday party, but not sure exactly when. I just know it was 9yrs prior to the party.