If you're worried about accidentally knocking up one of your bedroom conquests, don't fret. A study on a new contraceptive for men involving a skin patch that releases two hormones has shown promising results in reducing sperm production in men.
The patch is basically a combination of testosterone and Nestorone which is a new synthetic version of the hormone progestin. This testosterone-progestin combination was previously tested via pill, implant, and shots, but usually caused side effects like acne and changes in cholesterol levels. This new combination does a good job or suppressing sperm production without any of the negative effects.
The study proved that the patch had an effective rate of about 88 to 89% in producing very low sperm counts, with some men having a complete absence of sperm. But don't worry about your little swimmers, as the patch isn't permanent. Of course, these are only preliminary studies meaning there's still fine-tuning the details. So you might still want to stick to condoms just in case.