Sloppy Toppy

Recently, I've been very sexually active with my boyfriend. The last time we had sex (a few days ago) I did all the work; I just let him lay back and I was doing my thing. He's told me multiple times that I was really good, but today he texted me saying I should be more messy, and sloppy. How do I do that!?! I'm to nervous to try it because I don't want to look or sound gross! Any advice ladies?