Teen Titans, Vol. 3 #50 (2007)

Passage
Robin and the Titans remember Bart and celebrate his life with them rather than mourning his death. While they do so, members of the Justice League are caught by surprise and either captured or rendered unconcious by mysterious assailants.At the end of the service, Robin and Wonder Girl are left alone and are about to kiss before the Flash arrives to warn them. He is knocked unconcious, however, and the heroes witness the return of Superman and Flash from the future.
Release Date: 2007