Fear is an incredibly powerful aphrodisiac.
That means you don’t have to approach every encounter with genuine excitement and assuredness. Sometimes it’s good to be reticent, afraid. So long as you’ve consented and you trust anyone involved, being frightened of what is to come can be just fine. In fact, you might even enjoy it.
With a lot of the female libido being dependent on anticipation, build-up, words, foreplay, preludes to the main event than the actual finalized actions, naturally fear is a great tool when wielded correctly. It’s just another suspension of time, another little subplot on the way to the climax.