My 23 year old daughter introduced me to the man she's seeing around two months ago. It's been a long, serious relationship on her part but it's been one I don't approve of. Although I know she doesn't really care much about my approval, I have made it my responsibility to be as understanding about them as possible. L, the man she's seeing, along with my husband and I went for dinner a month ago. From the offset he gave us an odd vibe – he was rude to the waiters, started swearing loudly on his phone and at one point even had an argument with my daughter in front of us. The experience was humiliating for all of us. My husband intervened and told him not to dare talk to her like what and my daughter instantly took offense. She asked her father not to talk to her “to be husband” like that! Ever since then we haven't been in good terms. She has mentioned to my sister that she intends to marry him soon, but I won't ever let that happen while I'm alive.
It is clear that your daughter has taken more than just a keen liking for this man. She is blind to his faults to such an extreme extent, she won't defend her own father if it comes down to that. If he can misbehave with her in front of her parents, God only know how he treats her behind closed doors. Try to talk to your daughter without accusing or blaming her for what happened. Sit down with an open mind and tell her she can talk to you if there's ever anything that bothers her, and that you will support her with it. This way she is more prone to sharing her life with you and telling you what's wrong. Once you've gained her trust, gently explain to her that no one can ever change a man, no matter what they think. In her case, that is also true. Ask her to think about her decision to marry him before going ahead with it.