The Kiss the Boys Goodbye Dance took place in the Ritz in Cardiff on 20 January 1941.
When the Cardiff Space-Time Rift took them back in time, Toshiko Sato and Jack Harkness attended the dance.
Toshiko danced with George for a while but when Jack pulled them apart he reacted violently and the two fought. They were separated by the real Jack Harkness. (TV: Captain Jack Harkness)