I need it so bad

Shit, I shouldn't even be telling you this but it's like I can't stop thinking about it since it happened. She's on her knees between his spread legs, bra straps hanging loose off one shoulder like she didn't bother fixing them, and the lace on her panties is all stretched from how she's sitting back on her heels. One hand wrapped around him, the other just sort of resting on his thigh with these little silver bracelets sliding down her wrist every time she moves. The light's hitting her from the side so you can see the fine hairs on her arm standing up and the way her necklace keeps swinging forward and hitting his skin when she leans in closer. I keep replaying the part where she started talking. Real quiet at first, almost like she was embarrassed to say it out loud, but then it just came pouring out. "God, look at it," she said, fingers sliding slow up the shaft like she was measuring, "it's so fucking heavy." And the way her voice changed when she said heavy, like it surprised her. She had this little smile, not even looking up at him, just staring at what was in her hand. Told me later she didn't even plan to say anything, it just slipped. Then she got quieter. Started telling me how she used to think she'd never do this, never be the kind of wife who gets on her knees for someone else while her husband watches from the corner. Said something about how she used to feel guilty about it but now she just feels... warm. Like everything clicked into place. Kept stroking him the whole time she was talking, not even fast, just these long, lazy pulls like she had all night. The worst part, or the best part, depending how you look at it, was when she noticed I was hard in my pants. She laughed, not mean, just this soft little exhale, and she goes "you're really leaking through, huh?" Never stopped what she was doing though. Just kept going, eyes half-lidded, lips parted a little like she was concentrating. Her free hand came up and adjusted the necklace, tucking it behind her so it wouldn't keep hitting him, and I remember thinking that was such a wife thing to do. Practical. Even while she's got another man's cock in her fist. She asked him if he wanted her to use both hands. He didn't even answer, just made this sound, and she laughed again and switched positions, getting up higher on her knees so she could lean over more. The bra strap finally fell all the way down and she didn't fix it. Her hair kept getting in the way so she had to keep tucking it behind her ear with the back of her wrist, the one that wasn't busy. At one point she looked over at me, still stroking him, and she said "you okay over there?" Like I was the one who needed checking on. I couldn't even answer. She just smiled, turned back to what she was doing, and kept going like nothing happened. I still don't know if she meant for me to hear it or not, but right before she sped up she said something under her breath. Something about how good it felt to stop pretending. Does your wife ever get that look when she's got it in both hands?