Fucked Stud co worker!!!!!!!!

I consider myself to be a normal straight woman. I have been in a relationship with a wonderful man(the father of my child) for 3years and have never been sexually attracted to women but something just happened and here it goes:

So while at work minding my own business my manager introduced to me the newest associate except it I already knew this young lady we went to high school together. She has always been openly gay which never bothered me because I am not judgemental. We began talking and catching up when she expressed her feelings for a gay relative of mine and i said i would hook them hook up. long story short my relative wasnt interested. So she and I began having lunch as friends and I sensed the attraction but was never gonna act on it. After a late night at work us coworkers went and had drinks and while I wasnt wasted i was definately tipsy so she offered to drive me home. Well we ended up at her place with other workers so when everyone left we were gonna leave but as i headed for the door she grabbed me so seductively and kissed me. Next thing I kow Im naked and shes eating me like its her last meal. Then she pulls out her 8 inch strap on which she calls Mr. Goodbar and works my pussy for hours (with Joe "all the things your man wont do" palying on repeat) lickin my ass and rubbing my clit as she straps me. When shes done we just cuddle. I go home to my man feeling guilt and humiliation.

I feel horrible and i am afraid to tell my boyfriend. I have ruined our family. I wouldnt be afraid to tell him if she wans't a stud because if she were fem i dont think he would mind. On top of that I still hang out with her. What to do?????