You think you've been inside your mom for 2 to 3 hours so far. You can't be entirely sure, because you have no watch. You've had quite a good look around, even venturing through your mom's cervix and into her womb. Your mom had made it so you see, presumably to make it easier to explore. Whilst in her womb, you considered climbing into one of your mom's fallopian tubes and taking a look at her ovary, but you lost your nerve. You decide to go back into your mom's vagina, and it's at that moment you notice a change in the conditions. The womb seems to gotten considerably smaller for a start. After a few minutes, you climb through the cervix, and into her vagina. You immediately notice that the walls are covered in a thick layer of your mom's natural lubricating fluids. You also notice that they're now quite smooth, whereas before, they were slightly ribbed, like a concertina. It also now looks like her that the long tunnel that is her vagina, has gotten longer. Combined with a definite rise in temperature, you realise that your mom has become sexually aroused.
At first, think it's a result of your moving around inside a very sensitive part of her body. With that in your head, you decide to let your mom enjoy you even more, and you start wriggling around, moving up and down her tunnel, and licking the walls, this seems to make her even hotter, and you feel quite pleased with yourself for doing such a good job of being your own mom's personal, internal sex toy. It's while you start and trip deeper inside her vagina that you suddenly feel something rough, hot, and wet touch the soles of your feet and push you deeper inside your mom. You turn around in time to see something vanish back outside, but a few seconds later, and to your complete horror, you see an enormous tongue fill the entire tunnel behind you and quickly slide straight toward you. It's only a slight relief to realise that you're just out reach of the tongue. You then realise that it was combination of your moving, and the stimulus on the outside of your mom's genitals that made her so hot. You can hear muffled groans from outside, and decide to speed things up by going back to work as a sex toy at the top end of your mom's vagina. This has the desired effect, because a few minutes later, your mom has a pretty intense orgasm, which leaves you drenched in what feels like gallons of your mom's cum. You watch the tongue disappear back into the outside world, feeling a sense of relief that you won't end up sliding down somebody's throat. You guess that the tongue belonged to your dad. You can't be sure however, because your mom and dad have enjoyed an 'open marriage' for a numerous. Consequently, they've both had a number of lovers. In your mom's case, they've been both male and female. So, while you guess that it was your dad's tongue, you just don't know.
After about ten more minutes, you start hoping that your mom has gotten enough enjoyment from having you inside her reproductive system, and start moving down to the bottom end of her vagina, behind her labia. You get about half way, when you see the lips spread wide, parted by what, to your abject horror, you quickly realise is a humongous: