Ironically, here in the US even males have become bashful in the locker room. This has been much discussed at TFF. The once common communal shower is disappearing in the US. Many boys don't showers at all after gym now and newer schools are building showers with little individual stalls and curtains even in boy's showers. This is an enormous change from when I was a kid and we boys swam nude at YMCAs and summer camps.