I'm getting dinner ready and go to look for my brother in the house. I find him in Mom's room. She's out again. What is he doing? He pulls down her top, looking at her tits. Then he pulls up her dress, taking a look at her pussy. I can't believe what I'm seeing! I ask him what he's doing. He's obviously surprised to see me and starts stammering, trying to come up with an explanation. He doesn't have any real excuse, and I know what he was doing. But why? He says he's been lonely. Well, so have I. But I've been home taking care of everything, cooking, cleaning, helping out Mom while he's not around. He says he knows and he's sorry. I feel bad for him. I don't want to leave him like this. And I can't leave him alone with Mom. I don't trust him. He should have just stalked to me. I can help. What does he want me to do, touch him? I reach out and start rubbing my hand on my brothers very hard cock through his pants. He obviously like it. I pull his cock out and ask him if he likes how it feels. He says it feels amazing. I don't mind. This isn't so bad. I stroke his cock for a bit, then he says he wants me to put my mouth on it. Well, yeah, I've don't it before with other guys. I'm sure it wouldn't be that hard. I get on my knees and start sucking my brother's cock. I admit, I'm getting a little turned on with how hard he in my mouth. He says it might help if we move to the bed... even though Mom is still laying right there! Well, whatever helps him cum, I guess. I sit on the bed and keep sucking his cock. I'm starting to get wet, then he says we should have sex... with Mom right next to us! I admit to him that I've thought about it, but what if that is a step too far? We've come this far, and I do kinda want it. I lay on my back and let my brother rub his hard cock on my wet pussy. He slides it in, and I stifle the urge to moan. We have to be quiet. Mom is right there and could wake up at any moment if we are too loud. He wants me to rub my titties and my pussy for him. It turns me on how much he is getting into this, with our mother right next to us. I can tell he's getting close to cumming. I ask him what he is already thinking. I know he wants to cum on Mom's tits, and he wants me to jerk him off while he does. I sit up and start stroking his cock faster and faster, telling him to cum on Mom's tits. He shoots his massive, built up load of cum on her, coating Mom's tits. I can tell he feels so much better now. Any time he needs me, he just needs to let me know. I can help him out. That's what sisters are for.