Lucy gets direct.

After noting your interest in the expensive bottles of liquor, Lucy smiles, and saunters over to play bartender. Ana, still draped over Jack's arm, gets a pretty pink Cosmopolitan, Jack gets a J&B and Soda, and you request a Screwdriver, which Lucy makes with Reyka, a small batch Icelandic vodka you've never tasted, but have heard about.
"Your father isn't going to be mad that you're giving away his expensive stuff?"
Lucy laughs. "James, this isn't even close to his expensive stuff." She makes herself a Sapphire martini, dirty. "In his private stock, he has a single malt Islay that cost more than my first car."
"Well," you muse as you enjoy the nice mixed drink. She wasn't a bad little mixologist. "At least he has a discerning taste."
After another round, with the conversation light and enjoyable, you catch Ana in the corner of your eye, whispering in Jack's ear.
"I'm... I need to hit the head..."
"Oh, it's just..." Lucy starts, but Ana cuts her off with a look.
"I'll show him." her grin ruins any possible semblance of subterfuge she might be attempting. Lucy's return smile says she understands.
Ana takes Jack, who is grinning like an idiot, down the hall and out of sight. When leave, Lucy puts a hand on top of yours, pulling your attention back to her. She leans forward, and the top button of her golf shirt is popped, exposing the inner slopes of her modest, but perky tits.
"So, James." she purrs. "For years, I've invited you to have a drink with us, and you've always turned it down. What's different today?"
"I don't know..." your head is buzzing a little. You very vaguely hear a door open down the hall, and the faint sound of Ana giggling. "I guess it just kind of happened."
"You know I've always thought you were a super sweet guy. Ever since I was a teenager working the pro shop." She works her fingers in between yours, smiling. "Fell pretty far from the tree, if you ask me." You sigh.
"Yeah, sorry about that." When Lucy had been younger, around 20 if you remember correctly, there had been an... incident, and the details were pretty hush-hush. Lucy hadn't acquired her reputation as a good-time girl until later.
"Not your fault." She moves around the bar's end to plant herself in front of your stool, in between your knees. She holds her martini, picking the olive up by the stick and slowly pulling it off with her teeth. "Like I said, you're sweet... and you've been working out, too. I can tell." She squeezes your bicep.