Shinya no La La Laundry

"Shima" is a boy who's been a middle school student for only half a year so far.
He goes to a coin laundry to get his soiled underpants washed — in the middle of the night — so that his parents wouldn't find out. Upon going there, a lone woman appeared and began her laundry; but then she also started taking off her pants...!?
(Source: Tonari no Young Jump, translated)
Note: Originally published in Ultra Jump 2021-04