None. There are no nudity & obvious sexual scenes shown in this movie. A few passionless kissing scenes between the teenagers. One brief glimpse of make out scene between Madison & boy. However both are fully clothed(No nudity).
It is assumed that Rachel's friend has sex with a guy that Rachel likes (all you see is her friend coming out of a room and she is buttoning up her top).
Rachel and a boy she likes are seen in a room, some kissing, the boy thinks she is going to have sex with him but she doesn't.
2 passionless kisses, one for a school play and the other is for real.