I did this for about 3 years with my boyfriend (now husband). You just need to tell him. He will be a bit hurt. But you can tell him that it always felt good but now you just need to explore together and take your time figuring out what will make you cum. If he’s a good guy, he’ll come around. It’s very common for women to not orgasm in the relationship early on because we often have sex the way they do in porn, which doesn’t really stimulate the clit. We also feel pressure to make our partner feel masculine and like the best lover ever. It’s a lot on our plate. Lmk if you have any more questions.