the 'crotch' of the pants/shorts/pajamas
(..) - It's an amazing machine. Yes, indeed. Let's go. I'll see you in the desert next month. Be ready to have your ass handed to you. - You'll need more than that crotch rocket. - I got something for you. - What the hell was that all about? - Long story. I'll tell you later. Let's get out of here. NOS! (..)2001 The Fast and the Furious