Tonari no Onee-san ga Ero Sugite Shikottetara Kossori Nuite Kureta Hanashi

A pretty lady happened to sit beside me on the night bus.
Because of a sudden lucky pervert event, I got a hard-on and now needed to relieve my dick. So I secretly got it out, intending to jack off when I suddenly felt someone else's hand...?
It was the lady sitting beside me and she was holding my dick! No way, a convenient scenario like this can actually happen?
(Source: DLsite, translated)