Guy cums quick

Whenever I have sex with this guy there’s usually no foreplay he just goes straight in. He does initiate it by grabbing me and touching me inappropriately and I don’t resist him, I let him do that. I can feel him going in most the time but not always but I always moan each time like I know when he goes in but I don’t always feel it. Then after like 2-3 positions he cums, and it’s like about 15-20 min I feel. Mostly finishes in my mouth. He’s the first sexual partner I’ve been with and I’m usually shy about how to bring up how I can get off too but he asks each time after how it is and I say he’s a bit rough. The only time I felt him in me most was when we did doggystyle but as soon as he heard me moan in a way that was different and sounded like I enjoyed it way more he pulls out but he did ask if I liked it, I didn’t answer because I wasn’t sure what he said at first. Last time we did I rode him for like less than 5 min and he came. What should I do so I can have him last longer? I’m not sure if he can go another round either.