The only confession I remember about Blair going down on Chuck was someone saying they wanted the show to mention her going down on him. So I’m not sure.
I do know that in 3x18 Dorota said Blair was “going down” in the balloon dance game and Chuck said “too easy”. Then there was a smirk from both of them, which I think implied it’s easy to get Blair to “go down”. At least that’s the way I interpreted it.
Followers! Was there any other mentions of Blair going down on Chuck?