I would skip the baby oil and lotion and go get some Astro Glide, it will work better for you. A condom is a great idea also... and be sure to focus your attention to her pleasure. It's also a really good idea to have a vibe or at least a couple fingers stimulating her clit as you slide in. Good luck!

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Put me on wheels and I'll turn tricks.

Clever? Nah, I ran out of that years ago. But if you find this, let me know, k?
"The road goes ever on..." ~ Tolkien

In memory of my friend skip...
Go then, there are other worlds than these