Don't they have any cheap no-tell motels in your part of the world?
Attempting anal sex in a movie theater (which is, after all, a public place) will likely get you arrested for a sex crime. If convicted, your lives will be irrevocably changed and damaged. Don't do it.
As a manager for a major theater chain I would also recommend you don't do it. Due to sexual harassment concerns most theater managers including the one's in the chain i work for are not allowed to interact with customers who are having sex...so the only option is to call in the police. It is not a situation you want to be in. Trust me I've had to call in enough sex acts that started for very similar reasons as yours.
However If you really can't wait 2 weeks to have sex and you do find yourself in a movie theater then Oral is the only thing you would easily be able to get away with. Anything else and the auditorium checkers/Projectionists will be able to spot from a mile away.
P.S As a favor please don't do anything sexual in a theater it's rude, against the law and disrespectful to the people who have to sit in that seat after you not to mention the fact that it's possible children can see you.. It really would be in your best interest to find another way or even wait two weeks it wont be that bad I can assure you. =]
Good Luck with your situation I hope everything works out.
