Scientists in China are working on a new contraceptive for men that uses injections and magnets to heat up and SHRINK your family jewels, so they stop working for a while.
First, they inject nanoparticles made of iron oxide into your bloodstream. But you DON'T get the shot directly in your baby-maker, so that's good at least. Then they use magnets to draw the particles down toward your junk.
Once they're there, they HEAT UP, which somehow shrinks your dingles and makes them warmer. And when that happens, they can't make the baby batter required to get anyone pregnant.
They've only tried it on mice so far, but say the effects last about a week. And everything returns to its normal size after a month or two.