In doggie, act like an animal, throw your head back. Let loose with the noise, don't hold anything back. Bend your legs and look back at him if you can. If you dare, make him fuck your ass. At the least, tell him to lick it. This will intensify his doggie experience. If you wanna be nasty as anything, and if he likes nasty girls, when he's fucking your ass make him bring his cock round and put in in your mouth, suck it clean, then put it back in your ass. That's what the girls in the movies do, and the boys love it. You can also reach back and play with his balls as they swing, or even better, play with your clitty to increase your orgasms.