It sounds like you'd like Ai Girl, teacher/student, smut, and everything.

♪MONSTARR~ will eat all your cookies and steal your bishies~♪ Φ_Φ

I gave Ai Girl another try but I found out that I still didn't like it =.
Just very repetitive and dullish.
But the others I am reading. =)
Thank you all!~

maybe love triangle?

You know, you love me

If your okay with Manwha Replay is kinda what ur looking for but... erm It was rly good.

7th period is a secret

♪MONSTARR~ will eat all your cookies and steal your bishies~♪ Φ_Φ

I second 1/3 no Kareshi and also 7th period is a Secret
Also Chocolate Cosmos is a good one, and I think Houkago Wedding is one, oh and Ikenai Teacher Iketeru Darling

Not sure how Oresama Teacher will turn out, but maybe?

If you've ever thought or said "Nice Guys finish last" and really meant it, then you should probably read this LJ post by DivaLion. It's incredibly insightful whether you're male or female.

From a bumper sticker I like:
"If you're gonna ride my ass, at least pull my hair."

Sensei Yori mo Amaku: oneshot
Megane ni Koishite: Story 4
Jikiru de Haido na Kare: Story 3
Honnou Motto Midaretai: 1) From What Does This Lesson Lead To
Twins, Story 1

I've downloaded but never read Seiten Taisei. It's by Aihara Miki. This is complete scanned if you're interested.
Aisuru Hito By Yoshihara Yuki which is not all scanned but may have been picked up by AWillfulMuse. *Can't wait to read it!
One of my personal favs, non-smutty 🙁 , is Help!! by Fujiwara Kiyo which is completely scanned.

Hope this helps! I love smutty taboo shoujo, too.
EDIT: Forgot to add Pink no Indenshi story 1!! Also the manga, H, sounds promising but I've not read any.