I know I'm late to this, but simply liking breasts is not a fetish. However, liking breasts and nothing else, being aroused only by breasts, is debatable a fetish. Foot "fetishes" are usually not fetishes. They are technically partialisms, but they kind of go by the common name of foot fetish. I have a foot fetish, but I am aroused by vaginas as well, so it's a partialism in my case. I am not turned on by breasts, though. Nor am I turned on by butts. I'm sexually kind of strange. It is debatable whether breasts are part of natural sexual attraction. I think they are, as woman with bigger breasts are more likely to be able to produce more milk for babies, making them the desirable mate. I still do not like to reduce a woman to breast size, I don't feel that that is appropriate, as there are far more important characteristics, such as mental ones. Also, breast attraction kind of backfired in a way, as implants are being used by women to make them more desirable. So really, breasts don't mean anything.
Again, I know I'm late to this discussion, I just thought I would add to it anyway.