So my best friend, "Sarah" dated this guy named "Jeff," for about three months. He is a recovering heroin addict. He was super controlling their whole relationship. She couldn't leave the house without him. He wouldn't even let her hang out with me without him around. They broke up and it was ugly. He threatened to call child services on her and posted her nudes on Facebook. After they broke up, Sarah went back and started talking to her ex, "Matt," again. They were never official but everyone knew they were together. About two weeks after Matt and Sarah started talking again, she decided she missed Jeff. So she met up with him in a hotel in another town without telling anyone where she was going. Her and I were supposed to hang out that night but she blew me off for him and I couldn't get ahold of her. So I started freaking out. I finally got ahold of her and she told me she was in a hotel room with Jeff. I was angry. Very angry. One, because she blew me off, and two, she was screwing around with Jeff while she was telling Matt she loved him! So now, Sarah and Jeff are together and he made her quit talking to all of her friends except me. I can't be supportive of her relationship with him because of how he treated her the first time around and because he started doing heroin again when they broke up. Now she's mad at me because I won't support her and his relationship. Am I in the wrong for not being there for her?