Paramount Pictures has released a rather raunchy red band trailer for the romantic comedy No Strings Attached (via Cinema Blend), which stars Ashton Kutcher and Natalie Portman, and comes to theaters January 21st. Check out the trailer below, but beware, Ashton Kutcher's butt to follow:

No Strings Attached is directed by Ivan Reitman from a script by Elizabeth Meriwether.

In the comedy, Emma (Natalie Portman) and Adam (PElqZsqqoRv5ou||Ashton Kutcher) are life-long friends who almost ruin everything by having sex one morning. In order to protect their friendship, they make a pact to keep their relationship strictly "no strings attached." "No strings" means no jealousy, no expectations, no fighting, no flowers, no baby voices. It means they can do whatever they want, whenever they want, in whatever public place they want, as long as they don't fall in love. The questions become - Can you have sex without love getting in the way? And can their friendship survive?