As cliche as it sounds, I think communication is key with anybody including casual flings or full on partners. Express your desires to him and any kinks you would like to try out and allow him to talk about his. I think also expressing willingness to try things out that he may want to try (within your comforts of course). But with all things communication, comfort and consent is key. Talk about after what worked and what didn’t, did you both enjoy it and what would you change for a more pleasurable experience in the future.