How can I help my best friend realize trouble?

She and this guy have been “talking” for 4 months now, & she tries to throw hints at him about being in a serious relationship! He knows, but he avoids the hints, or he’ll be rude to her.
For example..she asked him if he wanted to make it work, and if they were going to ever make it somewhere. He text back, no and no! Like I don’t want my best friend to get hurt, and then when we talk about it she gets mad, and tells me she doesn’t want my help. I know I should leave her alone about it, but when it all falls down, who’s going to be there to wipe her tears for her? Not him! Does anyone agree with me?