It can be relatively light or carry some mild sexual innuendos but its all in good fun.
Reminds me of our bachelor parties of the 70's and 80's when we used to do something similar with food and drink and humiliate the groom to be
they do this out in the open in the city center and they announce a time and date, the students usually participate in good fun. I was quite suprised to see even parents and grandparents involved in the process.
My feeling is that they do this in good fun but has an undertone of wanting to keep the person grounded, basically saying congradulations, but remember you're still one of us.
Interesting enough Italians in Italy unlike Italians in North America have a very open mentality to sex or nudity, they still to this day dont understand why the fiasco with Janet Jackson at the superbowl was such a big deal in the US. They are actually more reserved about things that are related to violence. Images of body parts are quite open for humour or fashion or glamour but you dont find anywhere near as much violence in any tv or advertisement, unless your watching the news that are related to other parts of the world.
