On the night before the wedding, Basilio and Kitri "camp out" near a windmill and presumably make love, though this is never specified. He kisses her and nuzzles her a few times and then, after she lies down on top of him, he looks out at the audience watching the ballet as if to say "What are you doing here?" (this is intended to be funny). He then places his guitar so that the audience will not be able to see what they are doing.

Don Quixote fights the windmill thinking it's a giant, but we don't see the actual fight. We only see him falling off the sail of the windmill.

None; there's no dialogue.

Everybody drinks a bit during the wedding celebration.

None. This ballet is a sentimental comedy.