I have a feeling that my friend is in an abusive relationship, but I have no proof. Her boyfriend is always rude to her, and she doesn’t say anything back. When we go out together, he decides what she will get even if she isn’t in the mood. When I ask her about this, she laughs it off and says that she likes not having to make decisions, but I can’t imagine anyone wanting to be in a relationship where they have no say about anything to do with their lives. I feel as if she isn’t being honest with me or any of her other friends because she will think that we are judging her. Again, I have no proof; it’s just my instinct. How can I help her if she doesn’t tell me what’s really going on?
Instinct is a great thing and it’s important for you to take it seriously. However, when it comes to abuse in a relationship, only the people in it will really know what the dynamic between them is. If you see definite signs of abuse, you can and should call it out. Without your friend’s point of view, however, all you can do is tell her why you feel this way and reiterate that you are there if she ever needs someone to talk to. Keep your eyes open and offer support until you have more facts to go on. There’s little else you can do until then.

Why doesn’t my boyfriend seem to care when I threaten to leave him after an argument? Is this a sign that this relationship just isn’t as important to him as I like to think it is?
Why not just ask him? It could be a sign that you are not on the same page here, but you have to consider other factors that tell you whether he cares about you or not. Arguments lead to anger and that isn’t always a reliable way of gauging how someone really feels about another person.