I met an hb8 at a halloween party in a club. She actually approached me, since she liked my costume and thought I was attractive. We hung out for about a half hour and I eventually got her number. We've talked on the phone a couple of times and texted back and forth, but I'm afraid to fall in the ljbf zone. I realize that I should've already gone out w/ her by now, but we've both been really busy so i haven't even asked. I would like to invite her to my company's x-mas party, but don't know how I should ask her since we barely know each other. What's the best way to approach this? Should I go out with her first or ask her over the phone next time we talk? She's a really busy person, so the sooner I ask her the better.

Don't ask her on a date. Invite her to join you for something you can both do that would be fun. Maybe go back to the club again. Just do something together that would be fun. Then, while you're out, tell her "you need to come to this christmas party with me that my work is putting on. We'll have a blast." Or something like that. Since she's already having fun with you, she'd be interested in the offer.