After shooting the final episode ofCBS’ The Big Bang Theory, the stars took to social media to bid farewell after 12 seasons. "Here we go. One last time,"Mayim Bialik wrote, along with sharing a picture of the iconic lot water tower. Next to a picture of the cast hugging,Simon Helberg wrote, “We have done this 278 times. Before every show. For 12 years. Tonight we’ll do it for the last time.” The final episode will air May 16th.