summer blockbuster. But what's on your seat or on the floor beneath you? Here's nick watt. Reporter: This summer blockbuster season, you've got options. Pesky apes threatening the planet. Your... See More
summer blockbuster. But what's on your seat or on the floor beneath you? Here's nick watt. Reporter: This summer blockbuster season, you've got options. Pesky apes threatening the planet. Your standard homicidal super genius sexpot plot. Hello. And welcome to an evening with Annie and Jed. Reporter: Or maybe you like a farcical rom-com. If you go to the movies, whichever genre floats your boat, you're gonna find yourself packed inside a big dark room with a couple of hundred total strangers. What's that smell? What's that guy doing? What's that on my foot? Is that legal? That can't be clean. We went on a journey, swabbing theatres across the land and grilling the experts -- There's nothing more crazy than owning a movie theater. Reporter: -- To bring you the truth. There's no law that says they have to clean these seats. Yeah. That's disturbing. Reporter: What goes on inside the movie theater once the lights are down? Well, you could tell about what goes on inside a movie theater with what you find after. Reporter: Okay, go on. Used condoms. Reporter: Really? You got a romantic comedy playing, it's like the "Mile high club." And it's gonna happen in your theater, trust me. Reporter: Two weeks ago, this couple was arrested for indecent exposure after some hanky panky during a showing of "Godzilla." They've pleaded not guilty. Have you ever caught somebody in the moment? Yes. But if nobody complains, let them get away with it. Reporter: What I always complain about are the prices. Eight bucks for a bucket of popcorn that costs, wait for it, maybe eight cents to make? A 10,000% mark-up. Seriously? Daylight robbery? Well, not exactly. I make money by selling concessions. Reporter: Because, and here's a little-known fact, up to 70% of your ticket price goes to the studio and distributor. Leaving the theater owner with pocket change. And wait until you hear this. You gotta do little tricks to -- to get them to buy concessions. Reporter: Okay, like? Well, in my theater, I've got a exhaust pipe that runs from the popcorn machine into the actual auditorium. Reporter: You used to pipe the smell of popcorn into the auditorium? Oh, no, we still do pipe the smell of popcorn into the auditorium. Absolutely. Reporter: And if we didn't all fall prey at the concession stand, our ticket price would skyrocket. It's a nacho cheesy, hot diggety dog, trade off. But there is another problem with all that food. You know, a lot of theaters have problems. I don't want to say this. I won't say it. Reporter: Come on. You may have some little creatures running around your feet at night. Reporter: Roaches or rodents? You've gotta really make sure that you've got a good exterminator. God, theater owners are gonna kill me for this. You walk around and your shoes stick to the floor. So who's gonna wear sandals? God only knows what you're walking on. Reporter: Or what's walking on you. Bed bugs. Last month, there were reports of itching at a theatre in Virginia. And in 2010 the AMC empire in times square closed temporarily while exterminators culled some little critters. Remember I said we took samples? We're gonna go in and try to swab the seats and the floor without anybody noticing. We did this in a bunch of theatres in New York and Los Angeles and we came back to Dr. Philip Tierno to analyze our results. The seat and other areas of the theater are contaminated with the public that sat before you. Reporter: Most theaters are not problematic. But on theater seats, arm rests and even 3D glasses sealed in plastic, we found traces of all kinds of live organisms with big, scary names. Microscopic bugs that can cause things like food poisoning, boils and sinusitis. In a Manhattan cinema, we detected bacteria usually found in cattle and soil. Don't ask me. On seats in both L.A. And New York we found bacteria common in human feces, more understandable. Just as gross. Are there government laws as to how often you have to clean these chairs? No, unfortunately. There should be. Some theaters don't. I've been in theaters that -- that they don't -- they don't clean up. Reporter: The national association of theater owners had no comment. Okay, doc, so help us out, how do we not get that stuff in our mouths? If you're going to hit the arm rest, keep your hand in the air so that you can go to the dirty hand, this one that can touch anything including the outside of the popcorn box, and then you eat your popcorn with your good hand. Always have a "Good hand" and a "Bad hand." Reporter: Micrococcus luteus on the arm rest, you know what, that's forgivable. Almost. This is not. People who are texting while you're trying to watch the movie. You might as well bring a flashlight and shine it over your shoulder at the people behind you. Reporter: The Alamo drafthouse chain, which has a zero tolerance cell phone policy, banned Madonna from all their theatres for allegedly texting during "12 years a slave." Until Madonna apologizes, she's not welcome at the Alamo drafthouse. Reporter: And listen to this voicemail left by another patron kicked out for a similar crime. I didn't know that I wasn't supposed to text in your little crappy theater. Seems like she maybe had a little bit too much to drink and gave us a piece of her mind. And it was very charming in its own way. You know what? Reporter: The chain used this as a public service announcement before r-rated movies. So excuse me for using my phone in usa magnited states of America! They gotta go. And I've had that happen many times. Reporter: Robert bucksbaum, who, remember, will never break up a courting couple, will kick you out for cell phone use. You've got a stricter policy on cell phone use than you have on having sex in the theater? Absolutely. If you're not bothering another customer, you get away with as much as you want in a movie theater. Reporter: And that's why, when all's said and done, going to the movies is the most fun you can have with your clothes on. Or off. Perhaps. If you're those kind of people.
This transcript has been automatically generated and may not be 100% accurate.