Find a way to grow even more

Sophie: "There's got to be a way to grow, still! I refuse the busywork of destroying a... a thousand goddamn cities while every army in the world irradiates my ass with nukes."

For one moment in your life, you consider things a bit.

Sophie: "The two times that I grew were like, the best orgasms of my life. What if I went really hard on my fleshy joystick?"

Joystick might not be a fitting term here. More like a joybazooka.

You've heard that it's not a good idea masturbate with an iron grip, because it can ruin normal sex for you. Since you figure that you won't be having regular sex ever again, that seems like a moot point now. Then again getting a gorilla grip seems unfeasible anywho, because by this point you can't reach around your girth even with a bear hug.

None the matter! An intelligent woman like you will find her way. You saunter over to the closest continental fault line and jam your ramrod clean down its middle. Then, with both your arms and legs, you begin to heave the continents themselves back and forth in order to stimulate yourself. Slowly at first, but at a quickening pace.

The movements of your legs cause earthquakes of an immeasurable magnitude which extend to the entirety of both of the continental plates that you use, as well as on the edges of every adjoining plate. Every single building on both of these plates collapses into piles of matchsticks, and billions of people die, just from you trying to sate your dirty little needs. Realising this makes you a bit ashamed at first, but it only serves to hasten your grinding. You wish to erase all life from Earth to hide your shame.

Despite, and in large part due to the immense casualities, your method of masturbation is yielding results: you haven't even cum yet, and still you can feel both your body and cock growing, the latter at a much faster rate than the former. Soon it has become so thick than your arms and legs can't even grasp enough bedrock to crush against it. With one final push, you squash the two continents together, creating a mountain range twice as tall as the Himalayas, before the expansion of your seminal tract from the flood of cum rushing through forces the plates apart again into a vast alien landscape of a volcano range.

Your outburst of cum splits the whole planet apart - the first glob alone is enough to tear through the entire mantle and core and out through the other side of the planet. Not even slowing down, it annihilates the Moon in an instant, and travels at a superliminal speed to cleave out large portions of the asteroid belt.

Then you actually cum. Practically the whole solar system is engulfed in a whiteout. The other planets and the Sun are all washed away in an instant. Your seed is so thick that it instantly begins forming enormous black holes, but even those are sweeped away into the outer fringes of the galaxy by the torrent of your giantess spunk.

Needless to say, the Earth doesn't exist anymore. You're not sure how large you've grown because you've erased every other spec of matter from within a lightyear's radius, but to the viewer we can relay that the Earth would be comparable to about a single one of Sophie's cells. Your cock is so large that you can't see the end of it.

You buck and hump against the vast emptiness of space, unable to find a bearing.

Sophie: "Hmhhg! Graaah!! So. Much. Sexual. Frustration!!!"