Sorry, im a little confused.. please help!

*SPOILER* from known unknowns

So, if cuddy and house danced togethor that night in collage, when did that guy from, i think S3, come into play? he was the guy house had a dream about and remembered him because he danced with cuddy i thought.. Oh and they both went to collage in john hopkins right? He got expelled there from cheating..am i totally wrong here? xD

Thank you so much!!!!