Infatuation is an intense but short-lived feeling of passion or admiration for someone, often characterized by an overwhelming attraction that can be both exhilarating and consuming. It typically lacks the depth and emotional connection found in true love, often focusing more on physical attraction or idealized perceptions of the person. Infatuation can lead to obsessive thoughts and behaviors, but it usually fades as quickly as it arises, often revealing a more realistic view of the relationship.
Try to do the 3rd person view of looking for inflatuation (like looking for signs like staring, etc). Or, if you and your boyfriend are on solid terms, ask your friend. If she is your best friend, she won't be (too) offended by this. If you find that you friend is crushing, don't try to destroy it. Love/inflatuation is a state which can potentially destroy the bearer, so just let it be. There is not much you can do at this stage, but as long as your boyfriend stays with you, your friend will eventually move on.
A thory goes that love is a sign of maturity. As far as I'm concerned, teenage love is a bit overated, and is probably just a strain of inflatuation.