The sound that might be heard during the dark night, usually associated with kinky roleplay. The sound that is made when blowing on a miniature wistle hanging from a thong of some sort, used as a kinky turn on. Can also be used as a replacement for the F-word.
Oh my, last night I was folding laundry and I found a red thong in my moms dresser drawer, when I looked closely there was a miniature whistle hanging on it, then later that night I heard Fweeping coming from my parents room. I was like, WHAT THE FWEEP!?