I've got daughters.
Daughters who's gaydar is broken.

M just asked her buddy if he'd go to the prom with her. They are SENIORS.
He declined, said he wasn't going to have a date, he'd just be meeting all of them there.

We've been telling her that all the signals are there, give up on him, she of course does not want to believe. She MIGHT accept it now.

Of course, maybe he just doesn't like her and will show up with a date, a female one. But I'd bet against it.