Many sudden decisions were made, and then reversed, on this episode.
First, Sue fell for the news anchor Rod. She even took dance lessons from Will as a result - because Rod had asked her to be his partner for a dance-a-thon after one date - and seemed to display a sunny side. However, that quickly took a turn for the opposite after Rod was caught making out with his co-anchor in the studio.
It was back to evil (hilarious) Sue after that, as she booted Quinn off the Cheerios and called her a "disgrace."
Meanwhile, based on a dream he had about Rachel, Puck fell for her. Briefly. He rehearsed in his bedroom with his glee club co-member, asked if she wanted to make out and she said yes. Of course, she was picturing Puck's face as Finn's as she stuck her tongue down his throat. This felt oddly hashed together, especially when the new couple broke up after about 20 minutes of episode-time because Rachel still liked Finn and she could tell Puck had feelings for Quinn.
She has no idea he's the one that knocked her up, of course.
Then there was Will and Emma. She asked him for dance lessons and to try and mash up her first-dance wedding song (I Could Have Danced All Night) with Ken's (The Thong Song). The pair shared some intimate moments, made all the worse when Ken saw them because Emma was in her wedding gown for the lessons. Ken confroned Will about not discouraging Emma's feelings for him and also made the football playing glee club members choose:
There would now be gridiron practice on Thursdays and certain individuals had to choose if they wanted to sing or tackle. At first, Finn chose football because he was sick of having slushees thrown in his face. He wanted to be cool and accepted again.
But a pep talk from Will changed Finn's mind and he was able to convince Ken to forgo the idea of conflicting practices.
By the end of the episode, the glee club was back together again. They seem to often lose members for a few moments here and there, huh? They celebrated by all throwing a slushee in Will's face.