What should She Do?

When she was approached by her class rep on behalf of Prof. Igun, she laughed the offer of an A in exchange for sex off. A semester after the offer, Sade has taken her mind off the offer and has no qualms going to Prof. Igun’s office to submit an assingnment. Prof asks her to lock the door after herself because his air conditioner is off. After she drops her assignment, Prof asks Sade to get him a book from his shelf. Her back is turned to him and she doesn’t know that he has sneaked up behind her until her pulls up her blouse and bra in one swift move. She is too stunned to speak as the Prof squeezes her exposed breasts. There is knock on the door followed by the booming voice of Prof Alimi, the Dean and Iguns good friend. Igun pulls down Sade’s blouse and opens the door. Sade leaves the office.
A month later, there is a faculty student lecturers meet. The dean, Prof Alimi encourages female students to come forward to report cases of physical and sexual assault. Sade’s friend Bisi who is also aware of the incident is sitting beside her. Sade’s hand begins to go up but Bisi tells her beneath her breath not to try it. None of the students comes forward to lodge any complaint. After the meeting, Sade tells Bisi to be careful because Igun is the dean’s bosom friend. Any report against Igun would mean disaster for Sade. Bisi reminds Sade that she must be grateful since ‘nothing really happened’. Sade walks away wondering if she had actually been assaulted and what she should do.
What do you think Sade should do? Can Prof Igun’s act be proven? Is it assault? Please comment on this fictitious scenario.