Muffler
The. Muffler is the act of stuffing a girls panties into her anus, while she is asleep, leaving any air that escapes her anus, muffled.
Example:
" That drunk slut passed out after a hard ass pounding, so I couldn't resist giving her a nice muffler, her tiny little g-string fit right in her gaping hole"
" That drunk slut passed out after a hard ass pounding, so I couldn't resist giving her a nice muffler, her tiny little g-string fit right in her gaping hole"