Faking orgasms..

My boyfriend and I get really kinky when we’re together, and he asks when I’m about to cum. And I usually end up faking it because I know that I take much longer to reach climax than ‘normal’ women.. I feel terrible for lying, and want to have a genuine good time with him... but I also don’t want to make him hold out another 20/25 minutes just so I can get off! What should I do..