Fucked in the ass in the middle of a public car park!

I'm actually on my way to my appointment this evening. On the way to the car, I unexpectedly bump into an old school friend in the underground car park. He doesn't hesitate for long and just kisses me and then fucks me in my tight ass in the middle of the car park on the bonnet of a car! How do I explain to my date why I'm late and why my arsehole is completely stretched open?