Rectal temperature.

You take one look at her tight ass and decide to take her temperature. You grab the thermometer, but suddenly realise that you can't see any lubricant around. Unwilling to pass up the opportunity that is presented in front of you, you decide to improvise.

You crouch down so that your head is level with her pink asshole. You slide a hand between her legs and start to rub her clit. She squirms as you sink a finger into her pussy, which is already wet with anticipation. With one hand you part one of her ass cheeks, and with the other, you start to work her pussy juices into her asshole.

However, you decide it's still not getting moist enough, so more intensive work is needed. You use both hands to hold her round cheeks apart and then lap at her hole with your tongue. She is clearly enjoying this and starts to rub her pussy while you get to work. She moans as you start to work your tongue into her hole, pushing past the resistance and slowly widening the entrance.

By now she is furiously ramming two fingers into her pussy, and your tonguing becomes more frantic. You have a throbbing hard on. "Fuck the thermometer," you think, "I have a MUCH better instrument!"

Her ass is now wet and widened enough to start some serious entry. You position yourself behind her and slowly push forward. There is a lot of resistance, and feeling the way her ass wraps round your dick, you can tell this is new to her. She is obviously enjoying it, however, because although you planned a slow entry, she starts to push against you, until your cock is all the way into her ass. You can feel her fingers still vigourously thrusting into her pussy, and you try to build a rhythm to match this.

It is not long before your thrusting causes Julie to start to climax. "Oh GOD John, I'm COMING!" she yells. She comes hard, and her juices gush all over her hand. As she orgasms, her asshole tightens, setting you off immediately and you shoot hot spunk deep into her ass. Julie, although exhausted from just reaching a climax is set off a second time by you shooting your load into her puckered hole. She screams and pushes hard down on your cock, and you grab her nipples as she does this.

After a few seconds, you speak. "Well, everything seems to be in order here. Now, do you have any specific complaints that need looking into?"