Willingly Humiliated in Public. Stuck in a Wall

Jenny has a good career, a cozy apartment, and a generally boring, but comfortable life. She didn't set out to change any of that deliberately. She's just looking for a little bit of excitement in her life.  There's this abandoned mall she walks past on the way home every evening and inside of the mall is a hole in the wall that has been beckoning her for weeks. What starts as a harmless fascination turns in to an obsession.
Weeks later, she's stripping and climbing into the hole, getting herself stuck willingly so she can get off on the fantasy of being filled up while she can't even see the person doing it.  She doesn't expect to be caught in the act, and then have her mysterious lover bring his friends along to satisfy all her carnal desires. She just wants a little bit of excitement in life... and this humiliation is exactly what she needs.