Why did Sasuke take the team out to the hot springs when they were trying to see!
Question: Duh, because people usually take off their masks while in a hot spring
Answers: Duh, because people usually take off their masks while in a hot spring
because he would take off his mask if he did but he didn't
They were hoping that Kakashi would take off his mask while they were in the hot spring and he did but he wrapped a towel around his face instead.
Because normal people take off all of their clothing in a hotspring (including masks) and Kakashi is far from normal. Come on he is hooked on a perverted novel series and is always reading it on his free time.
Because usually people - we - strip off everything we wear when we step into hot springs. Sasuke believed that Kakashi would do the same, thus taking off the mask and showing them his true face. But..heh heh...he wrapped his face in the towel instead.