Her lips.

"You have great lips. Very kissable..."
"Yeah...?" she makes a kissy face. "Good for other things, too."
Your luck is holding strong it seems. "Oh, really? You'll have to show me sometime." You've been moving closer as you talk, and now your cock is comfortable resting against her ass. She moves up and down, rubbing your cock against her ass in a pleasing way.
"You'd like that, huh?" Miranda turns around and slides smoothly to her knees. Your heart begins to pound. Miranda rubs her nose against the underside of your shaft from base to tip, giving your cock head a little kiss when she reaches it. "Right here in the kitchen?"
You realize that Tom or Nicole could easily walk in at any moment. Sarah and Matt probably won't. For all I know, Sarah has her lips around Matt's cock right now. You can hear muffled voices vaguely in the direction of the bathroom, and an occasional bump or creak in the floorboard from upstairs.
"I'd let you blow me anywhere." you breathe.
"What if Nicole walked in? That wouldn't be very nice for her..." she's rubbing your cock as she talks, and her breath is hot on your member.
"What do you mean?" you are a little confused as to why Miranda is bringing up Nicole specifically. "She'd be embarrassed, sure..."
"You don't know? You haven't noticed?" Miranda strokes a little harder, with a tighter grip that makes you breathe more quickly.
"Noticed what?"
"That she's in love with you." Miranda smiles, and with that smile, spits on your dick before popping her lips over the head. You moan in pleasure and triumph, but you are also confused and shocked. In... love with me?
"Miranda, what do you mean..." you pant. "Did she tell you that?" Miranda sucks harder and goes deeper. "Miranda!" you want an answer despite the ungodly pleasure you are receiving.
"<pop>She didn't have to...it's obvious, though I guess maybe not obvious to everyone."
"We've been friends since we were kids." You don't want Miranda to stop, but you also need to process what she's saying. "Besides...she's always encouraged me to... pursue you..." Nicole teases you about Miranda more than encourages you, but it's the kind of teasing that feels like encouragement...you think. Now that you think on it, though...has there been a tinge of jealousy in her teasing?
"You're sweet, and she's naive." Miranda licks your cock from balls to tip. "I'd say that it feels bad to do this to her, but I'd be lying..." Miranda takes a deep breath, and then deepthroats your cock.
"Fuuuck..." your hands go to her head involuntarily as she gurgles and gags to get it all the way down. You aren't sure, but you think you hear voices again, muffled by walls. You think it's Nicole's voice. A male voice answers. It can only be Tom.
"Did you leave them alone to come flirt with me?" Miranda has come up for air, stroking your cock and looking up at you.
"I guess Tom went to the bathroom after her..."
"Poor girl. She's the perfect mark for him."
"What do you mean?"
"Well...." Miranda purses her lips. "Tom will jump on anyone who will have him, but what he really likes is sweet, innocent girls who don't know better. I'm sure Nicole won't be taken in by him, though."
A thump from the other room gives you pause. "...hard again?" Nicole's voice and you can just make out the words. A muffled response. "...don't know..." Nicole again.
"John, you seem a little distracted... do you want me to stop?"