one day your alone in your house when all of a sudden a knocking is heard behind the door
after opening you recognise a familiar face
"Erm Ayden ive been getting period pains and ive been wondering if you could go in there and sort it out?"
she looks nervous
"but ive got a dance audition and my costume is kinda.., Tight"
at this she injects you with some sort of shrinking potion
"well im sorry for this but it needs to be done you can have some fun with me when your done
at this she balances you upon her finger and shoves you up into her vagina

Later after changing

"I just need you to rub the walls down and flow the blood into this canister which will be inserted into my vaginal passage blocking your escape