There's no denying that having friends is integral to one's health and happiness. And a study from the Harvard School of Public Health has the data to prove it. The study found that friendship reduces physical ailments and increases contentment later in life. Previous research also showed that having a big group of buds lowers a guy’s stress levels, and reduces one's chance of becoming sick.

So if your significant other makes too much of a fuss over guy's night out, explain to her that men need both romantic and fraternal relationships to be happy, and the same goes for women and their girlfriends.

And if she finally understands why a man needs plenty of dude-time to be physically fit and mentally sound, congratulations! You've got yourself a keeper!