Why not try

Lucy was already looking at you suspiciously as if she was expecting some sort of catch so you decided you might as well make one up to see if you could get away with adding it.

“Fine, I was planning on bringing this up later but you already seem like you were gonna figure it out… I was thinking that whenever you had to help me when you got caught, it wouldn’t have to be right that second. Say for example If I had just had a blowjob off of Mom and then you needed to fulfil your end of our deal, I could ask you any time, any place to get on your knees and give me a blowjob. Within reason of course” you added, even surprising yourself at how well thought out your answer had been given that you had to think of it on the spot.

Honestly you could have gone another round here with Lucy but something told you that you should probably prepare for whatever Sarah still had up her sleeve and even after that, you had no idea what the rest of the night was going to entail other than a phone call to Emma.

“I knew you’d try something” Lucy said with a smile, looking like she had figured out a secret that hadn’t even existed moments ago.

“I’ve gotta try right?” you replied with a shrug.

“...So in this case where you had gotten a blowjob, when would you get me to return the favour? After you had helped me out of course” Lucy asked, still trying to put up the act that this was all hypothetical.

It felt like Lucy always had an air of self-confidence that you loved about her but something in you, your more dominant part, liked to see the more **** side of her that had only been surfacing more recently. She had gone back to laying down on her while holding her upper body slightly up, resting on her elbows so she could still talk normally with you giving you a chance to get yourself ready.

“Well after I’d helped you out…” you started to say, moving towards her before you hovered over her, straddling her so that you could get face to face with her while she was stuck underneath you.

Before you spoke, you saw that look in her eye that you had been looking for, the slightly nervous but also wildly excited about whatever was going to happen next.

“I was thinking I’d have to do it today. There’s a lot of options I could have chosen from but if I could make you do it, and you’d have no other choice… I’d wait until just after we had all sat down to eat dinner before giving you a signal to get under the table” you started to slowly explain, placing a hand on her stomach and tracing your fingers gently along her skin.

You could see she was hanging on your every word as you gave her the idea and with her so close in front of you, you couldn’t help but move just that little bit more towards her to start a kiss. She instantly moved to meet you as if the idea excited her just as much. She pushed back into you just as passionately as you were lusting after her and while things were heating up, you still made the effort to continue telling her what would happen whenever your lips were not touching.

“At first we would hide it from Mom and Sarah… maybe have me or you drop something… and you’d have to pick it up… but you know that we would start acting suspicious… and they would know exactly what you were doing” you continued, slowly drip feeding her more information and feeling her get more and more passionate in her responses to your kissing.

As you kissed you felt her stop holding herself up and she lay fully on the bed, now letting her use one of her hands to pull you fully on top of her. Her other hand snaked down to meet yours, interlocking your fingers and pulling your hand from where it had lay on her stomach to move further down.

You didn’t need guiding any further to get her point but you still let her do so, building up her desire with the pace she wanted to take things. Once she got your hand between her legs though, you took over, letting your fingers trace her lips before you pushed one and then another inside.

You stopped the kiss with her and just held her close, listening to her response to your movement and for every hitch in her breath, anything to tell you where to focus your efforts and what she was enjoying the most.

Lucy’s hand that had still been covering your own quickly moved away from yours once she knew you had gotten her message and it moved up towards her chest, her top getting in the way from letting you see what she was doing.

With her lay on her back, you couldn’t take her top off without her getting up but you still wanted to see what she was doing, rolling it up from the bottom so that it revealed her tits to you. Lucy rolled her nipple between her fingers and you could tell she was looking to maximise her pleasure even just a small amount more after what your fingers were doing to her.

You still had a hand free and you were able to hold yourself up while still using your free hand to focus on her other breast, loosely copying her own movements to gauge her preferences.

Lucy quickly leaned forward to start the kiss again and you felt your attention get split between what your hands were doing and properly returning the kiss with her.

Your description of a future scenario at the dinner table had also clearly not been forgotten as after her initial burst of lust that had made her throw herself forward at you, she leaned back to get closer to one of your ears.

“What else would you make me do?” she asked, her whispers sending tingles down your spine as you felt how excited she was to hear more.

You even felt her legs lightly squeeze around your hand as she squirmed in place, getting more worked up with everything you were doing to her.

“I could even wait until tomorrow. Not just Sarah and Mom watching you but we’d have a full table. All knowing you were worshipping your brother’s cock and not doing anything to stop you from making a scene. I bet they’d all be jealous as well. Wondering when they would next get a turn or if they could join you” you whispered back to her, feeling that your words had an immediate effect on her.

You could tell Lucy was building up to something big but you needed to talk to her more if you wanted to push her over the edge, making you try and think up something even more erotic for her to imagine.

Author's note: I will be taking a 2-week break in August(4th to the 18th) so wanted to give people a heads up before the month hit. Will still try to respond to comments if there are any but need a small break from writing to avoid burnout :)