You didn't mention if you're male or female yourself. I'm going to presume male. You know...I'm old enough to remember when girl watching was just something guys did. There was no shame or embarrassment in it. It was simply a guy-thing to do. It was even celebrated in song:

YouTube

Now we've come around to a place where one finds it to be an embarrassing, creepy & wrong thing to do. Oh well... times change.

What I've taught myself to do, whenever I have the urge to do anything I'd prefer not to do, is to simply allow that urge to be there, feel it fully, breathe into it, & perhaps even smile to it, allowing the urge (whatever it is) to dissipate on its own at its own pace (while not doing whatever it is I'd prefer not to do, of course.) It takes a bit of practice to learn to do this. But, over time, it becomes more-or-less second nature.

This practice is not necessarily going to make your urge to girl-watch go away. Again, assuming you're a guy, girl-watching is pretty-much hardwired into your brain, I believe. But this practice is at least a way of managing your urge to girl-watch (or to do something else you have the urge to do but would prefer not to.) This is a practice that is referred to as: compassionate abiding. Here's a link to a description of the practice:

Relieve Distress By Allowing It: Compassionate Abiding 101 | Mindset: Perspective Is Everything

May it be of benefit.