The Personal Touch — Caroline B. Cooney

Was Tim really an acronym for Terrible Infuriating Monster? Sunny was convinced that it was. Every single summer of her sixteen years Tim and his rich, snobbish parents returned to Sea's Edge to make her life miserable.
Now here he was again! It was bad enough to have to work afternoons and evenings when everyone else was at the beach and dating. It was worse yet not to have a boy to go out with, but to have Tim back again was the last straw - especially now that he had grown up to be tall, husky... and totally adorable.