A reason for it, why my versions of Buttercup and Trixie Tang are lesbian, (more personally and story reason):
I am a fan of romantic Cartoon pictures, and imagine therefore gladly some romantic relations out (see Toonlovers1 and 2). However it was to be found not simply a good mating for Trixie Tang and Buttercup.
Trixie is rich, but has actually somewhere nevertheless a good heart. Therefore I did not want a mating with Tad and Chad, or these yielded Remy Buxaplenty.
However am I for a relationship between Timmy Turner and Tootie, therefore Timmy was unfortunately also no possibility.
With Buttercup it was even still more difficult, since it is in my opinion not the type for a mating with a boy. And it was to be found so already heavily someone to suitable.
Story reason (to 95% invented):
Buttercups first relationship with Ace was already a flop.
And all following was not better also. When Buttecup went to the Megaville Elementary (Bleedman fan to know which I mean), began a short relationship with Zim (Invader Zim). Zim wanted to use their superpowers for its world army shank in truth actually only.
But Zim did not know that Ed (Ed, Edd n Eddy) was secretly with Buttercup in love. So comb it to the fight between the two, whereby Buttercup experienced the truth about Zim. Since then Buttercup began no more relationship with boys.
That could be done so long that she began sometime to develop an interest in girls.
After many try from Timmy Turner to impress Trixie. Trixie had developed really secret feelings for Timmy.
However Trixie had the same feelings for someone else: Timantha (in reality Timmy Turner in the episode “The Boy who would be queen”).
Timantha was for Trixie a correct friend, but Timantha unfortunately never dipped.
By these strange feelings thus also Trixie developed an interest in girls (briefly said: It is Timmys debt).
Therefore it began a relationship with Buttercup, when it likewise came to Megaville.
My English is not so good, but I hope that avowedly as I came on this idea.
And that the story reason also understandably works.