Knuckle Under

I have found a new way to masturbate without taking my briefs off. After I achieve an erection. I position my penis so the underside is against the material of the briefs. I then make a fist with my hand and rub the underside of my penis with my knuckles until I have an orgasm. This works best with tight underwear, because it keeps my penis in position. Try it. It's great