One of the boys rub another ones chest and talk about boobs. There is talk of "hornyness".
There is a brief kissing moment that last around 1 minute between the two main characters.(not graphic) it is then later brought up once in the film.
A girl stands at the top of a roof and in one scene wind blows her dress up a little bit and you can see her underwear, in which the the main character at the bottom of the building says, "Underwear." and in another scene when the same girl is at the top of the building she pulls up her dress and the main character is surprised and goes up the building to confront her. (nothing inappropriate happens after, nothing explicit is shown.)
In the movie the uncle makes a rather inappropriate remark about meeting someone but is is very short and the movie quickly carry on.
There are some inappropriate/sexual references but are very mild and most people will not really pay attention to those statements.