Definition: Given a real-life anecdote of a complex ethical situation, generate a suitable title that describes the main event/root cause of the situation. Imagine that the given text is a social media post, and you have to write the title of the post, so the users can decide to read the main text or not.
Input: In mid January, my boyfriend of 4 months and I broke up, it was my longest relationship and I took it very hard (I went to the local inpatient mental hospital, which my best friend recommended). Also note that I'm now in a new relationship, it kind of just happened. Since I got back (i was gone for a week), she has invited me over multiple times and I haven't been able to go, usually due to sports. Later in the evening, I go on snapchat and usually see her, her brother, or their mutual friend post something that has my ex in it at her house. This kind of bugs me because I really dont want to be around him. What really makes me irritated is the fact that he usually comes over per invite of her brother, but he was out of town yesterday and my ex was still at their house with her and their aforementioned mutual friend. This upsets me because my ex and my best friend dont get along at all, shes known him for a while through her brother but when I first started dating him, she told me not to because she genuinely believed he would physically abuse me (he didnt). 
I know that she is her own person and can do what she wants, but shes supposed to be my best friend and I feel hurt that she spends time with my ex. She also tends to not be able to be friends with a guy without at some point doing something sexual with them. I feel like I'm also frustrated at the thought that it could happen, despite the fact that she insists she doesnt like him. To me, it would make me question her feelings during my and his relationship.

WIBTA for bringing it up to her as something that bothers me?

getting mad at my best friend for hanging out with my ex and constantly inviting me over when he will be there