Am I in the wrong?

Since the beginning of the school year I have been friends with this girl named Lilly. She’s really sweet and fun and I love her, and I learned very early on that she has emotional regulation issues, and to not do anything that pisses her off. I joined the theatre club at my school, and made friends with a girl named Tessa, who was a mutual friend of Lilly. Tessa, being in theatre, introduced me to her friend Cici. I saw no problem with this and began to become friendly with her. Fast forward to today, me, Tessa, and Lilly were hanging out and I stole Tessa’s phone and took a bunch of *** pictures. She said she was going to send them to her friends, and Lilly asked if it was anyone she’d know. “Well, there’s… Cici?” Tessa said and I was like “No, dont send it to her, we just met” Lilly all the sudden got silent and angry. I eventually got her to talk and she told me that her and Cici had dated, but her and Cici had a fight which lead her to ghost Lilly. She also reminded me she had told me before not to talk to her if I met her, and I, at the time, agreed, however, I had forgotten and am now friends with Cici. We got in an argument and I told her I’m sorry that she felt like Cici had wronged her and agreed to not mention her anymore but I also said she had no right to control who I talked to and I wasnt gonna shut her out over drama I’m not even involved in, and now Lilly’s angry and refusing to talk to me. She thinks I’m a bad friend for talking to her ex when she strictly told me not to. I feel really bad for breaking my promise to my friend, but I also feel like I have every right to talk to people no matter what. Am I in the wrong here?