Flirting

Im not to sure if im showing my age or if flirting has evolved over the last few years. Today at work me and a work chum (she is a spritly 18 year old)  were standing around waiting for customers to come in. When waiting we thought it would be fun just to kind of tickle fight, i would like to say i kicked her ass but as usual she got the better of me (she will pay evantually).

Anyways in my day (pipe and slippers) this was prime flirting at its best, you get to touch that person, you have a laugh and it ends in a cuddle. I know she wasn't flirting and i wasn't flirting its just something we do. Now its just fighting, its no longer flirting, it has evolved, so my question is how the hell do you flirt nowadays? What is considered as flirting? I have been told many times i have flirted with customers, now our female clients are usually 30/40 somethings aged woman buying games for their kids. I know there is gonna be a difference between 18 and 28, but has it ever evolved or am i actually showing my age?