Caught Aunt Accidentally Naked

I was 25 and staying over at my aunt's place, she lives in another country so I was visiting for a week. I'd taken my girlfriend along, and one day we were just about to leave the house when I thought of something I needed to ask my aunt.

I knew she was upstairs somewhere so I called up, but there was no answer, so I walked to the top of the stairs and called again. A voice behind the door in front me called out "yes, what it is it?". Before I could answer, the door was flung open fully and my aunt was stood there, wearing absolutely nothing. She'd clearly just got out of the shower as her red hair was wet, both the hair on her head and the thick red bush between her legs, which I was facing straight towards as I was standing a couple of steps down from her. I'd never seen her naked before and she had a really beautiful body. I was totally stunned for a moment.

I stuttered out an embarrassed "oh, sorry..." and made to go down the stairs, when she replied "it's ok, I thought you were my husband. What did you want?". She remained facing me and made no attempt to cover herself, so I tried to remain calm and keep my glance away as I talked to her, though it was nearly impossible not to see her naked as she was right there in my peripheral vision. We finished the conversation and she went back into the bathroom, while I headed down to my girlfriend, now feeling very flustered and very conscious of being aroused too. "So did you find her?" she asked, as I tried to stop my head spinning over what I'd just seen.