Penny for the guy, guys?

Since when did "guys" become the generic form of address for a group of people?

I've noticed that kids are frequently spoken to like this, particularly when they're in a larger group. If, for instance, I take one of the mini-Ws to a party at a gym or sports centre (a popular choice of parents in south-west London), the staff will say "This way, guys..." when they're leading the youngsters from one part of the building to another.

The mini-Ws and their mates are not guys. They are children. They are kids. They are boys and girls. But I sense these alternative forms of address are now thought too twee, too patronising and too politically incorrect to use. "Guys" implies that the staff and the children are all on the same level. (Intellectually, I fear this may indeed be the case, but I'll leave that for another day.)

When we took the kids to Pizza Express yesterday, we were collectively addressed as "guys" by the waitress. Now, it's one thing for my young daughters to be "guys", but I think it's quite another for me and Mrs W to be tarred with the same bruschetta. We are Sir and Madam. Or if this is too olde worlde and square for the likes of Pizza Express, I'd suggest the conversation could happily progress without any formalities at all. "What can I get you?" is perfectly sufficient and doesn't need to have the new and increasingly ubiquitous "guys" added as an extra topping.

I watched as the waitress moved to another table and - as my friend Eve-Marie would say, this is the God's honest truth - she used the g-word to a middle-aged lady, her husband and his octogenarian mother. The old lady may not have heard that she was a guy and so no damage was done. Nevertheless, I think it's pretty shoddy treatment for someone who probably sat out the Blitz in an underground station.