You start by sitting down and telling him that he has been a very good son and you deserve a reward for being so obedient. You tell him that mom will touch herself for you, sit down and enjoy how you come for him and on top of him. You begin to take off your clothes, sensual, looking directly at him. Then you squat with your legs open and start touching yourself slowly, you tell him that you will come for him, that he likes how mom is doing it, that he is enjoying it as much as you. Finish with a squirt in this position, you tell him that all your fluids were on top of him, that you knew that was what he wanted and you love that he enjoys it. That you will continue to please him if he continues to be a good son.