Give her another toy

You get her a rabbit vibrator. "Here try this one next." You switch in on and show her how it works. You place the head of it at the opening of her pussy and slowly insert it, until the the probe on the side rested against her clit.

She stood there playing with her boobs while the toy did it's work on her clit.

You look at her face it is flushed and sweat is poring off of her. She looked so sexy. The smell of her pussy and the sight of her was making you as horny as hell.

You still have the four-inch vibrator Mrs Harris had just used. While her eyes are closed you move the vibrator up to your mouth and suck the end. You can taste her pussy.

You don't know how long you just stood there watching her but you quickly came to your senses when your girlfriend arrived home. You sent Mrs Harris to the bathroom to clean up.