Not at all! If he’s ready to have sex, by all means, take the reins. He’ll be grateful to you for it! If he’s not ready, then that’s another story, and you need to take it slow. Wait until he says or shows that he’s ready to take the next step. Don’t push.
But if you both agree that you’re ready to have sex, then go ahead! If you show him what to do, he’ll feel a lot more at ease and more confident.