It’s not graphic, visually or in language, and most will probably find the sequence humorous, but it’s essentially one long penis joke, specifically regarding the proper techniques for managing one while urinating.
It’s not a particularly adult scene, but it certainly could be an awkward one for younger viewers, or the adults watching with them.
What follows is an extended sequence where a character being portrayed as female has to deal with physically male organs for the first time.
The best example of this is probably a sequence in the first third of the movie when the character of Jack Black, who is being inhabited by a teenage girl, is forced to deal with the fact that he (or is it she?) needs to use the bathroom.