Your friend thinks it would be funny to block up a toilet in the boys’ bathroom
. It may seem funny to them at the time, but it is not a responsible or considerate thing to do. Blocking up a toilet can cause inconvenience for others, create a mess, and potentially damage the plumbing system.
Instead of participating in this kind of prank, it would be better to find more positive and harmless ways to have fun. Encourage your friend to think about the consequences of their actions and to consider how their actions may affect others.
It's important to always treat public spaces with respect and to consider how our actions impact those around us. Pranks like this may seem harmless, but they can ultimately cause more harm than they are worth.