It's been different (always good, though) with every lover, but this thread got me thinking about the first time I ever got naked with a partner. My high school girlfriend and I were curious about X-rated movies, having never seen one (no Internet, then), so we went to one and enjoyed parts of it, but left when the movie took a violent turn. We were definitely keyed up on the drive back.
She was house-sitting for vacationing friends, and invited me in. We discovered that we were both turned on, and the kind of light-to-moderate petting we'd been doing on our earlier dates wasn't enough. I asked her if she would like to get naked, and she gulped, nodded and said, "Yes." This was a big step for us...she was very religious and had said on earlier dates that touching her breasts inside her clothes, and her hips from outside her clothes, were her limits.
A wonderful memory, first opening my own shirt, unbuttoning hers and opening her bra. After some cuddling, she removed them entirely. Then, she let her hands follow mine as I unbuckled my belt, opened my jeans and slid them down, briefs and all. Her heart was pounding against my chest. She took a deep breath and stroked my hips, first cautiously, then with some passion. Finally, she brought my hands to her waist and the top of her own jeans, to let me know it was OK.
Undoing the top button, unzipping her, and then pulling her jeans down and sliding her panties off to join them, were thrilling, to say the least. I lowered myself onto her and remember my own heart pounding when I realized that my penis (completely hard by then, of course) was resting in her pubic hair. We just held each other and kissed, with racing pulses.
We knew we weren't ready to have intercourse, yet, but lying together like that for 15 minutes or so was Heaven. Eventually, we had to get "decent" again to go meet up with friends from her church, at a local pizza parlor...but before getting dressed, we just looked at each other in the fading summer evening light from the curtained windows, happy and vulnerable and trusting each other to keep the secret. She had lovely pink nipples, and a perfectly smooth white belly, with her hair down there making a beautiful contrast. She didn't seem shy any longer about looking at me, either...but I knew that this was a first for her, too, and her excitement was very "catching."
At dinner, we couldn't stop looking at each other and grinning. It was pure magic.