<human>: Provide a brief overview of the text.

Hey, long time lurker and first time poster. I'll try and include any information that might be useful. I tried to make it short and to the point. (Sorry if this doesn't belong in /r/relationships. just lmk)

Here's some background.
My childhood friend (lets call her Lacy) has always been very open with me. She's come to me for advice regarding various details in her life and we were very close. Recently she's been coming to me about sexual advice and those talks are always very interesting and eye opening. I don't often get to have a conversation with somebody who shares the same fetishes as I do so I don't mind talking about that stuff with her because I don't see her as a member of the opposite sex.

Me and my gf [23F] of 7 years have been thinking about threesomes recently. We're both bi and have been trying to look for another female. She brought up Lacy and while I never really though about Lacy like that, I figured what's the harm in asking? Apparently no longer being in her life was the consequence of asking her such a question. 

She didn't answer me right away, but instead asked to think about it. I said ok and a couple month later (today) I was bored and remembered that I asked Lacy. So I ask her if she's made up her mind to which she replies "Yep, don't f***ing text me. Oh and you'll never speak to me again lucky if you see me :)". This response baffled me because if it bothered her I would've been fine with her saying so and it didn't really mean that much to me to ask her. She wasn't my #1 choice and I could care less if she said no but was in no way expecting that type of reaction.

Basically, how do I salvage the relationship with Lacy?
<bot>: Offered childhood  friend of 13 years a threesome. Couple months later when I ask for her answer she says she doesn't want me in her life. How do I salvage her friendship?