A woman decides to record events of her friend’s sexual relationship with her deaf mute younger sister.

1) She discovers he is having an affair with her.
2) She decides on wanting to take him back.
3) She is tracking her sister her every move.
4) She uses a camcorder.
5) Her sister having a fight.

Hi IvyEight6,
Ok, a woman decides to record those sexual events:

Why?
To achieve what?
Why does she have to do that?
How is she going to do that?
What is stopping her?

To me, your logline has to include selling points.

I hope this helps.