Jeff decided that there wasn't much that interested him on his sisters lower half, but he still had some ideas of what to do with his sisters breasts, there was only one problem, they were now literal mountains to him, however thanks to the swimsuits tightness it created a sort of ramp for him to use, taking the opportunity Jeff slowly walks up the makeshift path, careful not to put to much weight on it incase it collapses.
As he walks across the clothing however he does notice some movement, fearing what could happen he quickly runs across the remaining space, finally reaching the top, however he notice's his efforts caused them clothing to moe down somewhat, exposing Cecilia's right nipple, he can't help but be amazed by the size, but he then also realises something else...it's erect!
"Hey little bro" a voice from nowhere appears, startling Jeff, he quickly looks and see his sister staring at him, her flasses resting on her forehead, before he can defend himself Cecilia covers her mouth, confused ny her actions he looks around only to see his huge erection, he realises its pointless trying to hide it now and simply waits for the abuse he may get for it, instead Cecilia removes her mouth to reveal a smile.
"Well well well, looks like you've been turned on by your sister..." she says mockingly, "Oh but don't worry, im flattered, and besides, since you've been such a good brother despite whats happened, im gonna give you a once in a lifetime experiance!" These words both scare and intrigue Jeff, he doesn't question it however, he just waits for her to finish.
Cecilia then grabs jeffs body with one hand and gently touches his cock with the other. "I know you've thought about me like this before, and don't worry, i have too, so allow me to do us both a favor", with that she pulls down the rest of the swimsuit, revealing her breasts for all to see, she then puts Jeff 'under' them, sticking his dick between the piles of flesh, Jeff couldn't believe it, he was about to get the worlds biggest titjob, from his sister no less!
She then gently pushed her breasts up and down, careful not to apply to much pressure incase it could injure Jeff, she then picks him back up and brings him to her face...
"Im gonna make you cum" Cecilia whispera slowly to Jeff before bringing him to her mouth, her giant lips envelop his cock with their warm touch, Jeff couldn't believe any of this, after a minute Jeff was ready to explode but he had one last idea.
"Cecilia, please put me on your breasts" he shouts in a satisfied voice, Cecilia is confused by this but agree's anyway, placing him on her left breast, Jeff then gets on his knees and begins to go wild on her giant nipple, humping, kissing and sucking it the best he can, Cecilia turns bright red, letting out soft moans of pleasure, she can sense his throbbing cock, Cecilia in a action driven by lust sits up fully and grabs Jeff, kissing his whole body before holding him to her face, he then procceds to cum, white fluid splatters all over Cecilia's face and mouth, in his exhaustion, jeff falls onto his sister's breasts and drifts off to sleep.
"I love you Cecilia" Jeff says before he fully passes out.
Cecilia looks at his small body, smiling and says...