He told her to prepare herself (candles, perfumes, clothing etc.) and then open the case that the mosquito is in and it will do the rest.
So that night the woman did as she was told, prepping herself and everything, then she lets go of the mosquito… but mosquito just stayed at the roof and did nothing.
Disappointedly the woman called the sex shop about the mosquito doing nothing, but the male cashier from before told her to give it a moment.
Long story short, the mosquito did nothing, and the woman called again for something to be done about this.
So the cashier begrudgingly agreed to come over her place to see what the problem was and if he could do something. Dialogue ensues:
Cashier: Ok where is that darn mosquito.
Woman: Up there on the roof.
He looks at the mosquito and says: OK LOOK! I WILL DEMONSTRATE THIS TO YOU FOR THE LAST TIME!
