I'd start by kissing you, and then lightly with one finger slowly stroke the front of your trousers... up and down, up and down. I'd gently slip my tongue into your mouth teasing it against yours to see how you respond.
I'd add a second finger to stroking your growing bulge... and when I feel your hands slide down my back to start kneading my ass I'd moan into your mouth with pleasure, deepening the kiss.
When I feel your cock begin to heat up and press into my fingers and your breathing quicken, I'd stop stroking and slowly take off your belt, taking my time to unbutton and unzip your pants, finally letting them drop to the floor.
I'd slide two fingers, one hand on either side of your hips, into the waistband of your boxers and begin pulling them down. Meanwhile continuing our kiss, swirling my tongue around yours.
When I've slid your boxers down I'd break our kiss with a grin, quickly kiss you on the cheek then drop to my knees in front of you, steadying myself by holding onto your hips.