How to educate 16-year-old adolescent men to hide their sister's underwear?
This is normal, don't be surprised, because boys who enter adolescence grow and develop rapidly, and their worship of sex organs is also strong. Use my sister's underwear. It will stand out and be sexy after the upgrade. Take it out when you tidy up his things, and buy him a pair of sexy protruding underwear. Do it. Don't blame him head-on.