I made a mistake with my best friend who is a girl.

I’m an 18-year-old guy and recently attended a high school party with my best friend, an 18-year-old girl I’ll call B. We’ve been friends for the past two years, and while I don’t have many close friends, she doesn’t either, aside from her boyfriend. I’ve always appreciated our friendship and never wanted more. At the party, her boyfriend wasn’t there, and B playfully asked me to lift her onto my shoulders. I went ahead and did it, not thinking much of it. Unfortunately, some people took pictures, and those photos ended up reaching her boyfriend, which understandably made him upset. While I don’t have strong feelings about her boyfriend, I care about B and want her to be happy since he’s a good guy. I suggested she talk to him several times, but she refused. I took responsibility for my actions and apologized, but it seems she hasn’t taken it to heart. She’s been distant ever since and doesn’t want to talk. Any advice on how to handle this situation?