Wasn't technically random, but it was a bit of a surprise

I have this friend I met online. We've been friends close to three years now. Last year, we were talking and she was talking about how one benefit of being fat is having large tits. I just laughed and said "how big we talking?" In response, she sent me a nude with her holding up on of her tits and said "they're this big."

I was a little shocked because she had a boyfriend at the time and we had never really flirted or talked sexually before. I didn't know what to say so I just said "oh yeah, they look nice." Looking back, I beat myself up for that. I feel like that's a clear sign she was interested in me