High school, the police get all up in their ass for not going to school, college students they are in an ass load of debt so they are pretty much forced to work. It makes more sense that they are adults.
I was giving an example of something to help you understand what I meant by tool, not saying it should be in that show. Every action that any character takes (or is on the receiving end) is a tool that should accomplish a specific goal.
I mean things can make sense even if it doesn’t have a goal but it will like you said feel forced. Sticking with the topic if 2 characters were to have sex there are plenty of situations where it can make sense, for example, a couple are out and it is cold so they head inside and the mood and atmosphere is perfect for them getting it on and so in this scene it makes sense but it must have some sort of goal like to get a message across or to serve as a literary device such as foreshadowing something or maybe being a metaphor for something. Basically, everything needs to have a purpose if it doesn’t then it is just filler, and most filler is bad.