My(22F) boyfriend (23M) said I’m the prettiest girl because I’m his girlfriend. But I feel weird about it.

So I asked my boyfriend if I am the prettiest girl he knows and he said “yes because you are my girlfriend.” But I feel weird about it because why can’t it just be a yes? It almost seems like I am not but he is saying that only because I am his girlfriend. I asked him why not just yes he said because what he said is true. It is because I am his girlfriend. But I guess he also said he doesn’t compare me with anyone else so that is reasonable. Still, if he said “yes because I love you,” it would have been a bit better… maybe he just wants me to be realistic. Some thoughts?