We love chatting with Timeflies about things like their first celeb crushes, but we can't resist putting them to the test from time to time. (No pun intended, we promise!)

When Cal Shapiro and Rob "Rez" Resnick stopped by the PopCrush studio, we challenged them to freestyle on the "fly." (OK, maybe that pun was intended.) We loaded up our handy pink bucket with all sorts of phrases, including "bromance," "selfie" and even "sexting."

Since the duo are total pros, they nailed the challenge -- and definitely had us cracking up! See Timeflies freestyle it up in the video above.