Blair and chuck nickname chair first met before pilot started dating relationship began season 1 episode victor victrola on and off relationship through seasons 1 amp 2 officially started dating in season 2 episode the goodbye gossip girl and broke up season 3 episode inglourious bassterds.
I think they do in the empire of the son which is season 4 episode 17 type it into youtube and it should work hope ive helped xoxo.
Dan and blair have sex for the first time serena gives a try at being gossip girl and a secret from chucks neardeath experience is revealed on.
There not dating in the season but they have a lot to do with each other there doing games and stuff but the last episode chuck says he loves blair and then they get together in season 3.
Blair tells chuck that shes ready to begin their wheelinganddealing life together but in true basshole form he effs it all up by intentionally humiliating dan then blair dumps him again the hora blair gets busy planning a new life with prince louis of monaco hugo becker which prompts some scary downwardspiral moments from chuck.
The episode of gossip girl where chuck trades blair for the empire hotel is inglorious basstards it is season 3 episode 17 3x17.
When he outs dan and serenas secret reunion season 2 episode 3 the dark night so dan and serena get back together at the start of season two but dan really wants to keep it a secret serena persuades him that they should reveal all at blairs upcoming party but then a gossip girl blast comes out showing the two of them kissing.