Strip naked

"First off, I need to have a good look at what I´m working with. Get naked."

Your heart beats faster as you look at Cassie. This was moving fast. Was she really expecting you to just get naked? You look at the window, the curtains arent closed. There arent many appartements on this height, but enough to make you feel watched.
Nyx raises one eyebrow, and you decide to not test her patience. Slowly, you get rid of your suit jacket, then your shirt, leaving your upper torso naked. You see Cassie get out of her shoes, but she cant open the zipper of her dress thats on her back.
"Help her." Nyx commands, and you quickly follow, opening your girlfriends dress not for yourself, but for Nyx, who watches you patiently.
Then you step out of your shoes and open your trousers. You hesitate a second before dropping them and look over to Cassie. She´s in her underwear, seemingly unsure of what to do now.
You drop your pants, but keep your boxers on. It just feels weird to get naked in front of what was basically a stranger.

Nyx looks upset at your hesitation. "Was I unclear? Completely naked."

Your heart beats faster, but you give yourself a push, take one deep breath and then-drop your pants. To your embarassement, your penis is rock-hard. The situation is just too exiting for you, you dont even know if its because of your adrenaline or because your turned on.
Nyx takes notice of your hard-on but doesnt say anything. Instead, she looks at Cassie.
Your girlfriend now drops her bra, revealing her cute breasts, then she pulls down her panties. You feel like your dick gets even harder watching the girl you love get naked.

"Very good." Nyx smiles.

So there you were, you and your girlfriend completely naked, in front of your girlfriends ex-girlfriend.

She stands up, and circles around you while you just stand there.

"Alright", she then says, "On to the next step."