<human>: I (22F) have remained friends with my ex's best friend [23M] ("Friend" for simplicity) who I knew before the relationship and he denies even talking to me if my ex asks.  I am now dating Friend's roommate [24M] ("Boyfriend").

It seems childish that he won't take responsibility for his decision to be friends with me.  Our friendship has really gone to hell since I started dating Boyfriend, but I'm quite tired of all the secrets.

Anyhow, the problem:  my ex saw me yesterday and commented to Friend that I had gained weight since we broke up (I've actually lost 10 pounds so I know he's just being mean).  Friend told Boyfriend who, in turn, told me.  My ex called me horrible names (including fat) our entire relationship so hearing that really upset me.  So I made the mistake of texting my ex, essentially telling him I don't give a damn what he thinks.

My ex has some serious anger problems, so after several long text messages telling me I "deserved" the verbal and emotional abuse he gave out throughout our relationship, he apparently starts blowing up Friend's phone, mad at him. As you can imagine, my phone rings about 2 minutes later and it's Boyfriend, upset because Friend is mad at him for telling me.  I apologized for the situation and told him I wasn't thinking about the repercussions.  I was sincere in that I'm sorry for the situation, (and obviously it was childish to go on a rant to my ex), but I really feel like Friend is at fault here.

I don't know how to get around this whole situation.  I can't have my ex coming between me and Boyfriend.  And I don't want to be a source of tension in Friend and Boyfriend's friendship.  Friend has been such a jerk lately, I could really care less if our friendship ends but I'll still have to see him all the time because he lives with Boyfriend.

Tell me if I'm delusional, but I don't really think I'm the problem here.  And if I am, how can I solve it?

Condense the text into a few key points
<bot>: Ex told friend I had gained weight.  Friend told boyfriend.  Boyfriend told me.  I blew up on ex and now everyone's mad.