For your ancient studies classes, a selection of Roman graffiti (not for the prudish: you have been warned):
Let water wash your feet clean and a slave wipe them dry; let a cloth cover the couch; take care of our linens.
[barracks of the Julian-Claudian gladiators; column in the peristyle]: Celadus the Thracian gladiator is the delight of all the girls.
To the one defecating here. Beware of the curse. If you look down on this curse, may you have an angry Jupiter for an enemy.
Theophilus, don’t perform oral sex on girls against the city wall like a dog.
Many more to be found here.