Many people believed that it would NEVER happen and that the worlds of the Arrowverse on The CW and the DC Film Universe would ever intertwine or cross over. Well now that has all been SHATTERED.
In the fourth episode of the CRISIS ON INFINITE EARTHS crossover, the two met as Ezra Miller’s THE FLASH met Grant Gustin’s THE FLASH. This happened as Oliver Queen, now as The Spectre gave Barry Allen a boost in his speed potential and allowed him to run into the speed force. While in there he is taken to the STAR Labs cortex and is met up by Miller.
The two Flashes then jokingly banter back and forth in disbelief before Miller disappears and then Gustin returns to the speed force.
The Mad Titan Podcast 