Well maybe I would want to help.

The words leave his mouth no different than they would have you or your mothers. Not everything is the same, though, as when he opens his mouth to try and say something else, your cum dribbles down his chin.

In a flash, your head turns to your mother to see her no longer painted in your seed, but turning back, neither is your brother. Did he only use his mouth? Why would he… oh.

“Hey, bro, would you rather you and mom both help me out when I get hard or just whoever wants to?”

He swallows the thick baby-batter before answering, making your cock throb against your thighs at the sight.

“We already both want to help you out. Why would we change anything?”

That’s new information. So since you’ve apparently had this new package for a long time, your family has had to deal with it just as long? And your brother has spent all that time wondering how it would be? And since you changed the previous result and had him swallow your load, he knows that he likes it now, and has previously taken shifts with your mother. The more you ponder the result, the more you fail realize your brother is peering back at you. He’s frowning, and it isn’t a good look for him.

Then, a mischievous thought pops into your horny brain. Maybe, he just needs to look better.

“What are you thinking about now, goofball. Is it something dirty”, he asks.

You look up and pointedly stare at him, answering, “It could be. Would you rather have taken after mom even more since puberty or have come with me to the gym since high school?”

He pauses, tapping his lips with a finger. His answer doesn’t surprise you. He’s always hated exercise.

“Taken after mom, goofball. You know I don’t do well with physical stuff like you.”

His face turns back to his breakfast, your mom just finishing hers. You take the time to nibble on some bacon while watching your brother. At first it seems that nothing has changed. Nothing you can see anyway. But, when you are about to lose interest, something pulls you back. His seat shifts beneath him and he has to adjust himself. His lips have puffed up a tad, and his cheeks are slightly tighter. You trail down to find that his belly is fuller than it was, being the only part of him to press against his T-shirt. Then you see his hips. Much like your mother, his hips have flared out dramatically. Your brother’s behind and thighs following suit, making him rise in his seat a good few inches. The sight reignites your lust. Your refractory period must be record-breaking low. You can make it better.

“Hey, bro, would you rather my balls swell with cum whenever I get horny, getting as big as mom’s breasts, or that when I cum in someone I can cum again instantly?”

“We don’t need you keeping us locked up all day, hitched to your… package. Why don’t you just get bigger?”

You feel the change begin, giddy about his choice, and note that your brother looks down at your lower half, licking his lips. You may not be a walking orgasm factory just yet, but you can blast a few gallons. Your balls fill themselves, semen production at an all time high. And it seems that he’s more than willing to help you out with that.

“I’m getting kind of wound up again. Could you help me out, bro. Please?”

“Yeah. Yeah, sure. Go up to your room. I’ll be up soon.”

You make a show of hefting your still growing sack, then turning and rubbing your growing erection as you walk towards the stairs. The new weight feels comfortably right. Like this is how it should be.

When you get to your room, you close the door and lay back on your bed, running your hands over your heavy cock. Then you wait.