There is not a lot that I keep from DP, he is someone I trust completely & I often like to hear his perspective as I can be black & white at times.l
I have had a friend play around on her partner before & use me as an excuse for not going home, her partner rang me at 2am knowing that we were meant to have been out together for my birthday. I didn't dump her in it but I refused to lie to him & I answered his questions with the facts - I told him she wasn't at my house, I had seen her earlier in the night & I wasn't sure where she was.

Your friend has no right to be miffed at you, she's the one being deceitful.