[Oh. He can gauge that Mark is nervous, so Rex tightens his grip protectively. If the roles were reversed and he were in Mark's shoes, he'd definitely be intimidated.]

Beeee-cause! When we're in our birthday suits as opposed to the super ones?

We don't need to look good, or stand for anything, or be thinkin' about the state of the world! Or anybody else for that matter.

[Rex's shoulders slump, his chest deflating a good deal. He really is doing his best to be honest.]

Also? I'm just really horny.