After being teased with the what-in-tarnation-are-they relationship between Sheldon and Amy for years, The Big Bang Theory tossed us a solid cliffhanger at the end of season ten: Sheldon, after being propositioned by a foxy lady scientist, high-tailed it to Princeton to do another “propo” activity and propose to Amy. It was cute! Bazinga! But whether it’ll actually lead to the duo being engaged is another story entirely, especially if Leonard’s ill-timed phone call is any indication. Watch all of the nerdy shenanigans unfold when TBBT returns to CBS on September 25.