Welcome to the forum, Morgan.
Sounds like a perfectly hard start, into poly. I find it incredibly generous of you to attempt to work with it.
You might want to think about wearing condoms yourself; I hate to say it, but if she's already lied, why wouldn't she lie about condoms. [also, what kind of idiot circles celebrate bareback with untested people?] Good for you for minding your own health. There are several threads here about sexual health, and bareback, and what not.
wishing you lots of luck (and can see that you will make some of your own)
Love is that condition in which the happiness of another person is essential to your own...
Robert A. Heinlein
Me: female, bi, (formerly hinge of a vee)
with FirstBoyFriend (FBF)(moderately long-distance)
and no longer with CurrentBoyFriend (CBF)(who now lives in a house far away-with stairs I can't climb)