If your gut instinct is telling you that your man is engaging in some secret afternoon delight with the babe next door in your bed, then it’s time to unleash your inner spy girl and put this Semen Detection Spy Kit to use.

The kit works by seeking out a protein found in seminal fluid called Prostate Specific Antigen (PSA). Apparently, it has been able to detect PSA from a 30-year-old semen stain, so holding onto sexy souvenirs is no longer a safe option.

As well as being an ideal way to catch a cheating mate, the semen detection kit could also be a useful tool for parents who are concerned that their teenage daughter is doing more than homework in her bedroom.