Decline, and make for an exit

"I would much rather... well, not have it at all, to be fair. No offense, of course." You take the book back, hugging it just below your breasts. "You've been more than a help, despite the... interesting results of this meeting. I appreciate the night, food, and bath, but I should probably be going."

"Very well," she sighs a bit, but doesn't seem too let down. "I suppose I should get changed, anyways. There's always things for me that need doing around here." She takes one more glance at your cock, and as if remembering something, looks back up. "Oh, and by the way, I couldn't help but make it incredibly virile, so any time you get even a few drops of cum inside a woman who could bear your child, it's almost guaranteed to knock them up." Still smiling, it's almost as if she's proud of this extra little fact, and turns to head back up the stairs, leaving you to let yourself out.

You're not sure what you expected, but you still shake your head in slight disbelief, walking back out towards the swamp. Once you're out of sight, you reach into your cleavage and pull out the ring. You take a quick look at the inscription, a series of snakes intertwined in pairs, each with another's tail in its mouth. Placing it on one of your fingers, you half expect your body to warp and change, but nothing happens, and it seems to simply be a decorative ring.

As you walk into the water, the dress again vanishes, and you quickly experience the rather awkward sensation of having your new, bare penis touch against the surface of the water. The day has not reached its midpoint, and so there's only a slight brightness flitting through the treetops, the air heavy and humid. Similar flying pests as the previous days, mosquitos and flies among them, fly in swarms just above the water, and by the time you've made it out of sight of the witch's home, many of the insects have landed much nearer to your groin that you would like, many of them even biting the tender flesh.

It takes quite a while of sloshing through the thick water, especially while trying to beat away the insects, but eventually you do reach the edge of the swamp, and move across the clearer water to walk up onto the beach. As soon as your nether regions leave the water, however, you are met with a deep and intense itch, centered directly on your groin. Looking down, your pussy is swollen with blood, many of the bugs having bit directly onto the labia, and it protrudes almost grotesquely from the surrounding skin, visibly throbbing with your heartbeat. Any attempt to itch the skin results in an immediate and intense burst of pleasure, and so even though you leave the water, the succubus's dress does not reappear. At the same time, your cock starts to twitch into an erection- it's been mostly unbitten, but still reacts to your pleasure.