This may be a stupid question, but would it be wrong to refer to my lap as my lap when I'm standing up? It doesn't sound right to me, but I don't really know what else to call it other than "quadriceps," which is really referring to the muscles, not my lap.
No. When you stand up, your lap just becomes part of your legs.
lap - noun
the top surface of the upper part of the legs of a person who is sitting down:
- Come and sit on my lap and I'll read you a story.
I believe it becomes your
crotch - the part of the human body between the legs where they join the torso.
this also does depend on one's definition of "lap".