until she leaves her boyfriend..leave her alone. its not right to mess with someone who's already committed to another person. you had your chance..she's moved onto someone who she really likes..why cant you just be happy for her? it just seems like she's flirting with you and maybe overstepping the line a little bit with the whole hot tub thing. you mentioned she was once in love with you..thats in the past..im guessing you really hurt her..probably the reason why you guys will just remain friends.
"We all take different paths in life, but no matter where we go, we take a little bit of each other everywhere."