Such a Bad Girl by Effie Campbell

A possessive professor.
A college student with a secret.

When forbidden attraction burns into obsession, nothing remains the same. Henry, a math professor, finds himself drawn into a dangerous relationship with Rebecca, a woman whose sweet face and teasing demeanour threatens to shatter every boundary he knows. As they spiral into power struggles, secret liaisons, and dark impulses, Henry must decide how far he is willing to go, and whether this whirlwind of a woman is worth losing everything he’s worked for.