The process of ingesting medicine via your urethra/penis.
"I was muzzle-loading some Viagra earlier today and I've been rock hard for 6 hours."
to place a metal rod in the urethra of the penis, utilized during sexual intercourse.
Man, have your girl take a shot at muzzle-loading, you'll thank me later.
the act of sticking a slim like object up a mans pee hole for pleasure
henry and john had a great night muzzle loading