"Back in Van after what was the sunniest/hottest experience in my Flash suit I do believe. This pap picture is my only current evidence. You could watch the @supergirlofficial crossover on March 28 though..." Gustin posted on Instagram.
The Supergirl episode is titled "Worlds Finest."
"Supergirl" airs Mondays on CBS at 8pm ET; "The Flash" airs Tuesdays on The CW at 8pm ET.