Go with Ben's idea

"Ben's right, it'll be funnier if I have a bit of groping," you smile. "Plus, more fun."

The pair walk closer, and you stare intently. Their short skirts give you a long look of thin, freckled legs, and when their legs sachet in a particular way you get a glance at their black-speckled panties. It's clear they're not wearing bras as their tits jiggle about under the tight confines of their shirt, their nipples just poking through. You could easily reach up their skirts and slap them both on the ass, or easily reach a hand into their shirt and have a good squeeze of their titties.