My girlfriend's younger sister, Sakura, who works in the product development department, used a duck mouth to make me ejaculate repeatedly!! Wearing prototype underwear with holes, I faced Sakura and couldn't help but get an erection and expose my glans... "If it's too big, I won't be able to get the data..." Sakura said, and started giving me a business-style blowjob by licking and playing with my glans with her duck mouth! The duck-style blowjob, where she licked and played with my glans, made me ejaculate with a suffocation! Then, "Your underwear will get dirty..." she used her penis to clean the blowjob! Sakura also played with my penis in various ways, such as playing with the glans with the slippery satin surface, playing with the glans by wrapping her neck with stockings, playing with my penis in a riding position... completely treating product development as a tool for abusing my penis...