Oh, yes

You were walking on the sidewalk with David behind you. In your haste this morning you forgot your panties and you didn't even noticed.

As you continued walking a strong gust of wind blew your skirt up. David was walking behind you and looked at the right time as the wind blew your skirt up. He was treated to the sight of your ass. You did not know it yet but your skirt was up and your ass was showing. David pulled his phone out as he started taking some pictures and videos of your ass.