Is it normal that my partner (21M) takes to long to ejaculate making me (20F) bored of sex?

While having intercurse my boyfriend takes so much time to cum (more than an hour) and needs to do it constantly fast to get there. This has made me really bored of sex. Since I have to endure such a long time it becomes rather a task than something that I genuinely enjoy.

I have tried to talk about it with my bf, but he says he doesn't know why it takes so long and how to change it. He even said he left masturbating to get there faster. But in the end it just ends in a pointless conversation as there is not much to do.

Of course I wouldn't leave my boyfriend because of bad sex. But when I think of having this type of sex life for the rest of my life I feel sorrow.

I wanted to know if it's normal to get bored during sex. And regarding taking to long, how do you change that?