At some point on a trip you'll often find yourself wanting to play a game. What better than a card game? They are often pretty portable. Then at this point why not a simple game that everyone knows like Uno? It's so simple, everyone draws a hand and then everyone plays a card that either matches the color or number... Or maybe you could play a wild card, skip, reverse, or whatnot to mix things up. Of course everyone has house rules. In setting up the game how many cards do you start with? Does the first player use the top card of the deck or can they just play whatever card in their hand they want? Can you stack draw cards?
Of course no one ever expects to play Sexy Uno. After Mattel fired a particularly unhinged wizard the wizard cursed the game in general with a rather family unfriendly hex. If you and whoever else you convinced decide to play uno when you take out the deck the cards have a chance of changing into Sexy Uno. This is true whether or not you are using an official deck, an unofficial deck, or even just a regular poker deck. The main changes to the cards is instead of the numbers going 0,1,2,3,4,5,6,7,8,9 they go -5, -4, -3, -2 ,-1, 1, 2, 3, 4, 5. The colors don't change, but what the colors represent do. As the curse/deck is slightly sentient the effects tend to change depending on the group that's playing. Are kids and parents playing? Then there are going to probably be age cards. Is it mostly a sausage fest? Well maybe there'll be some gender cards.
Then of course if you are playing with the special rule that if you play a 7 you swap hands with someone else, or if you play a 0 everyone rotates hands... well that adapts into swapping bodies. Although the exact numbers may either be -5/3 or 2/5 depending on whether you believe 0 represents 10 or 0. The curse after all is rather accommodating to house rules/beliefs.
Now comes to the big question... How the heck do the transformations even work? Well it's simple. When you draw a card the color and number indicate the type of change and magnitude of the change. The change activates when you draw the card and reverses when you play the cards. So in theory if you win the game and no one has played a swap card you'll go right back to normal at the end of the game. Reverse not only reverses play order but also changes the magnitude of all current changes until reversed again, skip is merely just a skip, drawing is just drawing cards, and then the wild cards allow the person who played it to change the current color... also it makes the instincts of players go a bit wild for a short period.
The winner is then deemed the winner, the game ends, and then reality alters with the winner getting a slight pull in how things adjust. Now comes for the serious question.