You wake up the next morning

Slowly and somewhat reluctantly, you groggily rouse from an intensely erotic dream about a threesome with Suzy and Diane. You really want to go back to the dream, but today is a work day and you can't be sleeping in. You open your eyes and find you're alone in the bed. There's a folded piece of paper on Suzy's pillow. Uncoordinated and bleary-eyed, you slowly unfold it and squint to read the words.

Thank you for a wonderful evening. We should do this again sometime.
-Diane

P.S. Here's something for your collection. You've earned it.

Beneath the note is a pair of black lacy panties, the same ones Diane was wearing last night. You smirk to yourself as you remember the night you and Suzy took Diane out for drinks the night she filed for divorce. Suzy had started to get tipsy and began reminiscing about her wilder college days, and you had joined in with a few stories of your own. At one point, she mentioned that you used to have a collection of panties worn by girls you've fucked. You weren't planning on talking about that in front of Diane, but the three of you had a good laugh at your "youthful indiscretions" and you playfully boasted about the size and variety of your collection. When Suzy slipped off to the restroom, Diane asked if you still had your collection.

"Yes," you answered.

She smiled and looked down to the side. Her cheeks, already reddened from the ****, blushed a little more. She had a little smirk on her lips as she asked, "Do you still, um, 'collect new trophies,' if you know what I mean?"

You hesitated, not sure if it was safe to answer truthfully. "Would you tell Suzy if I did?" you finally asked.

She shook her head. "No, I wouldn't do that to you," she said earnestly. She bit her lip and started idly twirling a strand of her hair as she finally looked up into your face and said, "Maybe one day you can add my panties to your collection."

"I would love that," you said without even thinking about it first.

She leaned in closer, her lips less than an inch away from your face. You could feel the heat of her skin and the coolness of her breath for an infinitely long moment before she whispered, "But you'll have to earn them first." The words hung in the air for what felt like an eternity before Suzy returned from the restroom (apparently more drunk than you had realized before considering how wobbly her legs were).

Well, now you've earned them. You congratulate yourself and savor your victory by holding the crotch of the panties up to your nose and breathing in deeply. Her sweet and musky aroma fills your nostrils and your head begins to swim all over again as you relive in your mind how you vigorously and thoroughly defiled your sister-in-law last night and enjoyed every moment of it.

Once you've finished savoring your prize, you take Diane's panties up to the attic where you've hidden away your "Box of Conquests." You've had to upgrade to a bigger box since your college days and have re-labeled it "sports trophies" to sound more innocuous. You give Diane's panties one more sniff before tossing them on top of the mountain of underwear inside the box.