Please, why don't you read your own links? From that link that you posted:

Aug. 14: . . . The two go out for dinner, return to the apartment and have sex during which a condom breaks.

Aug. 15: . . . Miss A hosts a party for Assange at her home, afterward reportedly tweeting this to friends: "Sitting outside ... nearly freezing, with the world’s coolest people. It’s pretty amazing!"

Clearly the party happened after the first incident, and so did the tweet.