Come within hugging distance of your significant other (I learned that it is supposed to be 6 ft or 2 meters for my European readers) and these pixilated hearts begin to flash. Proof that you are in love! During your normal activities only two and a half hearts will light up on your shirt. Get close again to the other (of course, he/she needs to wear this special shirt) and you are in full charge, blinking crazy like a Christmas tree. Go too far astray from the source of your affections and you’ll drop back down to two and a half hearts again. Got it? At Think Geek.