Now I'd like to point out something. I've noticed that in many Sonic yaoi comics, stories and even a few pictures that one of the two in the couple ends up having a child. Now I say that is completely INSANE, but I thought that if that's what's going to be done, I might as well show how I'd think the child would look like. So here ya have it; one picture with 9 Sonic yaoi couple's kids. I only chose ones that I liked and/or are pretty popular (not in order of my favorites. X3). Maybe, if ya'all like this picture, I might do more of the couples kids.
So without further ado, I might as well introduce each of them. The order is left to right, starting from the high-left corner.

Gadget- Sontails's son. Yes, he obviously inherited Sonic's speed and looks, but he also took Tails's intellegence, which he would rather use. He loves to build things with Tails, but would help Sonic anyday.

Alewar- KnuxEspio's son. He is very protective over friends and family, despite his enemy's size. His name was given to him because of this by Knuckles (Alewar means "guardian of all").

Spear- Knuxonic's son. This little speedster took Sonic's speed and rashness and Knuckles's determination. He always wants to join Sonic on every adventure, even when he knows he can't. Thanks to his rashness, he always finds a way to get into trouble.

Shyla- Shadails's daughter. She is very anti-social, just like Shadow, and is sometimes considered shy. However, loyalty is at least her second nature, just like Tails, and she is willing to help at any time of crisis. She also knows how to fly like Tails, but would rather run like Shadow.

Nirav- Sonilver's son. Everywhere he goes you would expect him to be in an over-sized sweater, for he is really sensitive to the cold thanks to Silver being in an extremely warm place for most of his life. He is also naive thanks to Silver, but very passionate and warm-hearted thanks to Sonic, and always enjoys a hug from even the coldest of hearts. (Solo picture and bio- http://fav.me/d5f9aw1)

Kendra- Silvails's daughter. She has the outgoing personality of Tails and is always willing to help, yet she has also taken Silver's gullibleness (no offese Silver lovers!), which sometimes makes her easy to trick. But she isn't dumb; she is smart enough to learned to fly just like Tails.

Taavi- Shadilver's son. Some consider him a goth or emo thanks to his dull-colored appearance, but when you look into his yellow eyes that he has inherited from Silver, you'll know that there's more than what meets the eye. He has two dominant sides of himself— one being timid and the other determined and sacrificive, like Shadow.

Kali- Knuxadow's son. Anti-social and quiet, some consider Kali as mute. But some call him "silent but deadly", for he is known to pack a powerful punch like Knuckles can. He is strong with speed as well, thanks to Shadow, so he can be a pretty tough opponent if you decide to get on his nerves.

Sebes- Sonadow's son. The son of two speed demons, this little guy can travel real fast! His name speaks truth to his speedy talents (Sebes means "fast" in Hungarian). However, knowing that he is the son of two chaotic figures, G.U.N. has given Sebes a power ring collar (not shown in pic) which restrains any chaotic power within him.

There ya have it! Sorry for the long discription, but I hope ya'all like these guys!
And don't leave a bad comment! If you don't like, then just leave. Thank you!

(Edited: Fixed spelling error. X3)