My boyfriend called me by his girl best friends name

Problem/goal:

Me and my boyfriend had been together for a month and we were cuddling in school, this was after class and he randomly called me "I love you "vi". I was still shocked but I didn't say anything about it.

Him and violet had been friends since elementary but they have no contact now, violet told me in person that she will ignore "Liam" since I'm here now, and she studied somewhere far. I want to confront Liam but I don't want to upset him, I know it's a red flag. My name is far from vi so It's probably now a coincidence. My name is Ayesha, like me and my boyfriend, he would let me borrow his phone and he has been the best so far.

Now it's been four days and I wonder if he only dated me because of looks, I mean violet was a top student and she was so friendly, she had looks just not the body, I'm not hating but she's just chubby and I'm really slim, I think that's the only reason why Liam dated me. His password for his phone is her birthday.

Update:

I confronted about it and he hugged me saying "it was just a mistake, I'm sorry baby" and he added it with something similar to these lines "violet is already far away, and nandito ka naman." I asked some friends also and they told me that I should leave him, I'm upset I love him yet I don't think that he loves me sincerely. Maybe it's just because I have the body while violet has the personality? I'm gonna leave him probably at the end of the month, thank you for the advice!