Trying to help a friend...

I am trying to help my friend see that her current boyfriend is trouble and that she is better of without him in her life it seems as though he is using her for money and takes advantage of her all the time...I recently pointed this out to her but she tells me that he is not and says that he pays his own way but it just doesn’t seem like that. She told him that I said that and when I saw him he started acting really rude to me and said that he had a job and he pays for his own way and everybody agreed that he does not use her for money it’s like nobody can see what he’s like. I just don’t trust him and my friend would be so much better with someone else but she is just so blinded by love. I always try and welcome him into the friendship group but he just acts so rude to me but he acts nice to my friend and pretends he loves her but I can tell it’s just an act and that he is just using her. How can I make her see that she is making the wrong choice and she deserves so much better than him? I previously lost another one of my friends before this by trying to warn them that their boyfriend was trouble so I really need to go about this without pushing my current friend away...any advice?