[DemolitionRed]

Certain types of public nudity under UK law is deemed as "indecent exposure". This Act currently includes genital exposure with intent to shock a person/people and also includes "simulated sex/buggery" which is something Aaron did with Joel.
Such acts can carry penalty of up to two years imprisonment or a very hefty fine.

Every time something like this goes on in the house, the producers need time to talk to in house lawyers. It was likely legal advice that got Aaron evicted and not Joel reporting his disdain in the diary room.