For what? They did nothing wrong? There’s no implication of rape nor is he using the r-word in an offensive manner, the r-word has two meanings and this OBBVISE context he’s using the second meaning.
re·tard
verb
/riˈtärd/
- delay or hold back in terms of progress, development, or accomplishment. "our progress was retarded by unforeseen difficulties"
Bruh in the lyrics he's talking about a girl, then saying something about holding someone back, like its weird. Either way the should address it.