Seeing my gf smile. First I think she looks so pretty and pure, and then I think how much I want to drown that cute face in pleasure, and see her smile while I fuck her brains out or while she has my cum in her face and body. It's very hot. Also when she gives me that needy horny puppy look of hers and when she unconsciously rubs her erect nipples through her clothes (with her arms) when she's aroused