Are you sexually active with your current guy? If so, it might be an idea to introduce the notion with a little "near-ballbusting" foreplay. Use the sexual activity afterwards as the "reward" for "playing along".

An idea would be to have him on his back with you on your hands and knees over him, then gently bring your knee to press in his groin area. When he makes a face or makes a groaning sound, tell him how much it turns you on and gets you excites when he does that, then give him a tight hug and kiss him all over his neck while breathing harder. Then straddle him and get his penis inside you and ride him until he ejaculates. That'll reinforce to him that he should start playing that way.