"But Cadance, I'm straight."

"So is spaghetti until it gets wet."

That line never gets old.

"Do you have any idea how long I've fantasized about this? How many times I've rubbed one out imagining how you'd look between my legs like this?"
Twilight couldn't talk with her mouth full.

What would Twilight say if she could?

"You'll learn as he did that your place, your purpose is to serve me. To please me. He can tell you first hoof how well I take care of mine." Twilight furrowed her eyes. "Your defiance only makes this hotter for me. But rest assured, by tomorrow, you'll be begging for me to let you put your tongue in my pussy!"

And the Twilight turned matters around by casting a spell to let her horn vibrate violently.
This caught Cadance off-guard, allowing Twilight to overwhelm her with pleasure, followed by her re-negotiating the deal.

Cadance just smiled softly. "I know, Twilight. I know... But I do . Just as much as I like stallions. And as surely as I love Shining. And had things been different, I might just as soon have married you ."

What's he's trying to say is he wants the whole set the family set. Got to catch them all

Cadance smiled. "Well, now... I have something that you want... to make a deal." She stood up and walked around behind their chairs. "Therefore, there must be something that you have... that I want ... to make a deal. And it just so happens that there is something that I want." Twilight felt Cadance's hoof on her shoulder. "Something that I have wanted for a very long time."

Cadance, you're too pink to be the Merovingian and you're not purple enough to be Circe.

"You know... as royalty, your marriage could be a very powerful bargaining chip. Prince Abraxas of Zebrica will be at the summit. You know what they say, once you go striped ..." Cadance joked. Twilight either ignored or didn't hear her. "Queen Rain Shine's son is only a little younger than you... I do hear the Kirin are quite fiery lovers..." Twilight remained unmoved. "I did catch wind of a rumor from Mount Aris that Sky Beak finalized his divorce..."

Oh my gosh.

Cadance just smiled softly. "I know, Twilight. I know... But I do. Just as much as I like stallions. And as surely as I love Shining. And had things been different, I might just as soon have married you."

"Cadance, I... I don't know what to say... I'm sorry?"

Oh my!

"You want Shining Armor for your sperm donor?" Cadance asked as she grinned. "I can make that happen!"

Oh my goodness!

"That's a neat trick,”(—— Twilight breathed.

Twilight balked. "What!? Shining has the hots for Mom?"

Yeah that ending totally could be mistaken for Chrysalis.