Shawn Peters puzzles it out in The Boston Globe:
So why is check-in a turn-on? Do hotel chains put pheromones in their air-conditioning units? Is there something in the newness of the location, giving couples a risk-free opportunity to “take their act on the road”? Or is it as simple as the fact that hotels are places where someone else will replenish the linens and even deliver overpriced club sandwiches to your door, creating an atmosphere of freedom that encourages friskiness?
The first time Sara and I ever stayed in a hotel together was toward the end of college, when an older friend from Brandeis got married in New Jersey. We drove down and arrived at an offramp-adjacent Sheraton, knowing that between the ceremony, reception, and our need to drive home first thing in the morning, we might spend less than an hour in the hotel awake. But I remember checking into the hotel, opening the door of our “deluxe” room with a view of the Garden State Parkway, and feeling like carrying Sara over the threshold. It was our honeymoon suite, even though we weren’t the ones getting hitched. It also set a precedent that would be upheld for more than 16 years and counting.
In that time, I’ve tried to figure out what’s behind the “hotel sex” mind-set. When possible to do so without incurring dirty looks or harassment suits, I’ve talked to other couples to see if it was a cultural thing or age specific, but it seems nearly universal. My buddy Matt had a hypothesis that since many couples meet at a time when they are living with roommates or, worse, their families, hotel rooms, with their steel doors and deadbolts, offer a level of privacy they can get nowhere else. After all, there’s no such thing as a “Do not disturb” sign when you’re cohabitating with a bunch of roomies who are privy to every creak of your bedsprings.