Fuck that's hot.
The sight of both your hands working together to give you pleasure is such a turn on.
Slide that finger deeper and faster now. Stop stroking with the other hand and pull on your balls. Massage them while you fuck your ass.
Wow, I'm getting really close now. I can feel myself reaching the edge. My fingers are really fucking my pussy now, feeling the juices build inside me.
Continue after you're played with your balls for a little while (as long as you want no more than a minute)