I am having troubble remembering the title but I remember some details.

In a woman a short-haired woman is worried whether her boyfriend prefers women with long hair. So she wears a wig to fool him. Whenever they have sex, the woman is having harrd time enjoying it, because she is keeping worried on her wig whenever it almost falls off her head during the sex.

When she suddenly loses her wig while having sex with the boyfriend, he notices her short hair. Then she become fearful that he will break up with her. But he assures her that he was fine with their relationship.

I will add some more details. I will describe the characters.

The woman's hair is so short that she looks like a guy. Her short hair is close enough to be a military haircut.

Her wig is so long it reaches past her shoulders.

The guy is wearing glasses I think.

By the way the manga is josei romance

First chapter of Anata ga Watashi to Kurashitara.

~4400 manga completed
~1700 ongoing...

Yes, you are correct. That is the title I forgot. when I went to read the manga Anata ga Watashi to Kurashitara. you mentioned, it was exactly the one I was trying to remember. You have given me the answer. Thank you very much.