Our happy hour fact to amaze the drunks in the pub.

One in 10 mature couples still react to their partner with the same intensity as those in the first stages of romantic love.

Researchers scanned the brains of couples who had been together for at least 20 years, and others who had recently met. After being shown a picture of their mate, 10 percent of the older couples displayed the same burst of pleasure-producing dopamine as the new couples did.

Previous research suggests that this giddy, can't-keep-your-hands-off-each-other brain reaction starts to fade after about 15 months.

While we are very happy for the lucky 10 percent whose passion for each other burns eternal, we do have an important piece of advice for any and all older lovebirds: Get a room.