Even supposing that it was sexual innuendo, that doesn't mean he was hitting on her. Straight men and women have conversations filled with sexual innuendo all the time.
They are co-workers. He should have showed some restraint. BUT academics are supposed to be famous for free and unfettered flow of ideas, so that gives him some slack.
Playing on the sexual innuendo of a paper on bat fellatio doesn't need to mean he was hitting on her. More likely it was a subtle form of sexual harassment.
I thought most of the time sexual harassment happened because the aggressor basically wants the victim to sexually submit (i.e. have sex). It might not lead to a more direct, "have sex with me if you want to get promoted," but I see little point in harassment for the sake of harassment.
>I thought most of the time sexual harassment happened because the aggressor basically wants the victim to sexually submit (i.e. have sex).
Sexual harassment is harassment - behaviour intended to intimidate, disturb, offend, threaten someone - that uses sexuality as a vector. It's extraordinarily naive to assume sexual harassment isn't taking place if the aggressor's goal is not to elicit submission to sex itself.