Hajimete no Hitozuma episode 3

Natsuna helping her son, Kazuhiro, to move out. Kazuhiro introduces her mom to his upperclassman who already graduated and working as moving company. Thanks to his upperclassman, Koizumi, the moving process went smoothly. But when Koizumi asks for the moving fee, Natsuna becomes puzzled. Then Koizumi tells her that she should have sex to pay the moving fee instead of money.