So you want something where the girl is forced into sexual situations?
Katie's Corruption
Elena's Life
Lily of the Valley
Like really, I'm gonna be straight with you, almost any game with female protagonist and corruption tags are gonna get that. It's like looking for any needle in a needle stack.
If you want something where the player has more freedom
Coceter Chronicles - my absolute favorite game
Project SAGE - my second favorite in terms of female protagonist.
Now, those two are a little unique in that they probably have more player freedom than even most male protags in games, allowing you to shape your character's personality in many ways.
Other great female protagonist games include
I Love Daddy - Daddy being the only male character in the game, she gets plenty of bisexual content
High Life - I admit, this one is only in its first version, but it already has a lot of promise, some of those promises include a bisexual character.
Chloe18 - This one isn't exactly what I'd call great, but it's incredibly entertaining.
Jessica O'Niel's Hard News - I haven't gotten far in this one, but what I've played so far is good.
Seraphim Academy - shameless self plug. Female protagonist, bisexual, nothing like Anna's Exciting Affection though.