Actually, this was more or less of a challenge between me and Gamepad pone (www.deviantart.com/project-88) which we came up with out of the blue when we were chatting in Steam xP.  
Well, it looks like I’ve still managed to make you kiss your own ass in SFM, Gamepad!) xddd
 
 
MercFox: (talking to himself) He-he, this Increased Speed and Flexibility potion turned out to be very useful indeed! Was able to finish all my tasks like four times faster than usual! Hm-m, not sure why anypony would need its ‘extra-flexibility’ feature though… I felt like a dachshund made of rubber most of the time, especially when was running somewhere… So weird. Dunno if Gamepad has any ideas about it. Anyway, drinking it together and then splitting up was an interesting idea: each one of us would find he’s own interesting use to the same potion. Now, I wonder what he came up with after an hour… (entering the room)  
Gamepad: (kisses his plot again and again while standing twisted as a bagel) Oh my..! I never could’ve thought my butt tastes like a chocolate flan! It is SO delicious..! (kiss) ..and tasty! (kiss) …and softy! (kiss) Oh boy, I have the tastiest butt ever! (kiss) I’m so in love with my sexy posterior! (kiss) But I should definitely try kissing MercFox’s plot as well! Oh! It must taste like mango! (kiss)  
MercFox: … (Standing shocked with his mouth wide open. Slowly walks away trying not to make any noice in order not to be spotted by his friend)  
XP