Forget an ecchi manga about male who knows the user of a sexy social media account

The male MC follows this account and then manages to find out a social media account that post sexy image of her body. All that is iconic about it, is that the breasts or butt i forget which one has one or two mole, that male mc knows it.

Ofc he stumbles upon fellow student who has that similar mole. Then said female student manages to blackmail him due to him getting into ecchi situation with her.