i can't cum for my boyfriend, even when he eats me out or fingers me

me and my boyfriend have been dating 9 months. he took my virginity and evert time we've have sex, i've been able to make him cum, but i've never came for him before. even when he eats me out or fingers me. i feel the pleasure and the climax even when i self pleasure myself. but nothing comes out. he says it's his "mission" to make me cum because he hates that i can make him feel so good that he cums, but he can't return the favor. i've tried explaining to him that i feel a climax, but nothing comes out, and he still wants to make me do it. i mean i'm happy he wants to pleasure me like that. but i don't want him to be only thinking of trying to get me to cum the whole time we are doing it. each round lasts about an hour or more. but i can never finish. is there something wrong with me? is there a scientific term for what's happening to me? i've read that other people have trouble cumming for their partners. but i can't even make myself do it. i just need some help as to what's happening with me.

Thanks

He definitely wants a lot. It doesn't matter if you don't cum, fake it till you make it. It took me about 9 months to properly grasp what makes my gf cum, and now I can make her cum from penetration alone every time. You definitely won't be cumming from fingering anytime soon, it's mainly clit stimulation, especially with the tongue, it takes a while, I find it a lot harder to make her cum with just my tongue and it usually takes a while 15-30 mins. It's more about the duration of constant stimulation that makes a girl cum, and requires consistent rhythmic movements and moderate of the tongue on the clit and slightly above, it's all about technique and experience. One break in the rhythm and your likely to get further away from orgasm.

Penetration is a different story, he's got to have big equipment for you cum from penetration alone, and it happens a lot easier without a condom. He's got to repeatedly hit the g-spot with the same theory explained above- moderate pressure, rhythm and consistency. However I found that one or two breaks in the rhythm is okay, but anymore than that is going to bring you back where you started. Orgasm from penetration works best in missionary position, with your legs wide apart, knees tucked and feet flat on the bed.

TLDR: He's not very experienced