I'm too old to bother with all this new-fangled PC nonsense you young'uns go in for which involves not being a xenophobic bastard.
You need to be very careful with this one.
The only thing you can do is trust your instinct.
Mocking people who buy their clothes in Asda was made illegal in 2009.
You'll spend hours poking it with a stick.
As Dostoevsky wrote, 'don't do the crime if you can't do the time'.