1. A normal kiss burns 6.4 calories per minute. A passionate kiss can burn up to 20 calories per minute. That's even more than swimming, which burns 12 calories in one minute, just like jumping rope.
2. Today, an average kiss lasts more than 12 seconds. In the 1980s, couples came up for air sooner than that: back then an average kiss lasted a mere 5.5 seconds.