Rejection is telling a man you don't think of him as a valuable human being and that basically everyone would be better off if he killed himself. This traumatic experience changes his personality forever and makes his life harder. Virtually all men, save for the most popular, powerful or attractive, live while carrying the trauma of at least one rejection, which they can't even talk about because society will demonize and persecute them as misogynist terrorists.
Rape is when a female's whole being is validated and a sexual fantasy of hers is fulfilled. She then can pretend to be a victim to get sympathy and even more validation from society.
The two are NOT the same.
Also, male on male rape is anal and actually painful, while male on female rape uses genitals that were designed to feel pleasure during sex, so don't even try to compare the two.