Yes...but not quite how she expects it.

You go around behind the bound Mallory and spank her ass. She moans happily.

"You really want to get fucked, don't you?"
"Yes, Master."
"In that case, let's do it..."

You run your cock along the outside of her pussy, causing her to moan some more.

...then you surprise her by yanking the ass plug out suddenly and shoving your cock into the now-loosened hole!

"Fuck- you're too big for there!"
"Nonsense. A slut like you can take it. I'm not your first, am I?"
"You are. I've never let a guy take my ass before."
"Good. I'm your first and last. You will only let me take that ass, right Slave?"
"Yes, Master. Fill me up more than anyone ever has."

You find that your entry is made easier as Mallory loosens up for you. You fill her ass up, so you just start to fuck it.

"You're the second ass I've taken today."
"I know. It was so hot."
"You want to be where she was, don't you?"
"Yes, I'd love for you two to dominate me," Mallory says with a smile.
"You want me to fuck your ass again?"
"Yes, Master."
"You want that Teacher to fuck your pussy with a big, black strap-on?"
"Oh yes, Master!"
"Do you want us to make the Gym Teacher fuck your pussy?"
"Yes, Master!"

Mallory cums right then and there, squeezing your dick super-tight for a minute. You manage to hang on.

You stop fucking, but keep talking to her.

"We'll need to know the name of that guy you let fuck you," you say.
"I'll tell you, Master."
"We'll have to make sure that he doesn't talk. Any suggestions?"
"I know just the way. That is, of course, if you'll let me fuck him again. Just to help out, of course."
"He was smaller than me, wasn't he?"
"Much much smaller, Master. I did most of the work to cum, if I'm being honest."
"I understand and I give you permission. When should we set the trap," you ask.