Voyeur Or Just Curious?

I've been back and forth. When I married her mom, Annie was 15. She was very pretty but also very shy. My wife often laughed and said she thought Annie had a crush on me and I just passed it off. When she was 17, I was in the laundry (closed door) ironing and she opened the door and peaked in. I was in light blue, tight boxer briefs that didn't leave much to the imagination. She said, "Sorry I heard something. I didn't know you were in here." and closed the door. I felt like she took a quick glance as she did. But she reopened the door a couple minutes later to tell me about a tooth that was hurting and asked me to see if I saw a cavity or chip. Maybe it was an excuse, but I played it off and looked in her mouth. I had put her on my insurance and told her me or her mom could take her to the dentist. Then she sat on a chair and just started chatting. I felt like she was using it as an excuse to stay in there. I downplayed it with her (due to biological dad issues with abandonment) but I won't go into that. But I caught her looking a few when I woukd look ever to her. I mentioned it to her mom that night and she laughed and said, " Get over it." She explained that nudity wasn't an issue with her and her kids (Annie has an older brother away in the military). About a year later (Annie was 18), she barged into our bedroom and saw me completely naked. She just froze, got an eye full, and said "I'm sorry. I didnt know you were here." I was so shocked I didn't say anything, but later told her it was probably as embarrassing to me as it was her, but that it happens. I told my wife, and she just thinks it was an accident and said "She's 18. I'm sure it wasn't life or death for her or you."

Now, 3 years after the first incident, she's walked in on me 8 or 9 times when i was completely naked, came into the bathroom while I was taking a shower to get shampoo from our cabinet several times. (Our shower is 100% glass.). Now Annie doesn't say "I'm sorry" or make any excuses. Each time I mention it to my wife and she thinks it isn't a big deal at all. The interesting thing to me is Annie has not mentioned it to her mom once, and my wife has not said anything to Annie either.