Sexy Lifeguard

I have worked for a pool for several years now and so has this girl who is a couple years older than i. in fact she is the main reason i come back year after year. her sexy athletic body barely fits into her swimsuit and i stare at her constantly. she often catches me and gives me flirtatious looks. time and time again we talk about sexual subjects while we work concessions together and most of the time i just fanasize about the crazy things i want to do to her. i can never tell if she is flirting with me or just playing with my horny 17 year old mind...does anyone have any advice to what i should do to find out?