How do i handle this??

Ok ladies i find myself in a conundrum, i have no idea what to do. Please help. This is going to sound odd but please bear with me, its a long one.

I have a six year old son, he is very much a boys boy, he loves getting dirty, playing with cars and trucks etc. He is an only child. Recently i was packing my things for our trip away, i couldnt find several pairs of my nice lacy knickers, some bras and some high heels. I knew i had only seen them recently so it wasnt like i had misplaced them, they were definitely gone. At first i thought that perhaps our cleaner had taken them (horrible i know but theres no one else in the household except my husband and our son, and noone is present when she works).

Imagine my surprise when i went to pack my sons bag and found several pairs of my knickers, bras and high heels hidden in the bottom drawer in my sons room. I was in absolute shock because it was the last thing i expected. He was sleeping peacefully and i sat there and laughed because it was so crazy. I wasnt at all mad at him, just confused.

I didn't want to accuse him of anything or make him think he was in trouble, i want him to know the lines of communication are open with me, and that hes safe with whatever he says. so the next morning i asked him if he had seen some items because i couldnt find them anywhere. He said no. I asked if he could help me check his room because i had looked everywhere else and i needed those lost items for our trip away. He offered to help but was very hesitant about me going in that drawer, going so far as to try and block it with his foot. I got the drawer open and his reaction broke my heart. He immediately began crying, he had been sprung. I pulled him in for a cuddle and told him repeatedly that hes not in trouble, im not mad. I asked him why he had taken them and he replied he didnt know. So i thought a different tactic might work. I tried asking about each particular item, what was it that he liked about each one for him to take them. It was as i expected, that each item had a detail that he found pretty. He said that he wanted to go shopping with me to help me buy some other pretty things. I told him that we could do that soon, but i asked him to please not take my things because it upsets me when i cant find them and i thought someone had stolen them. I said that if he likes looking at pretty things its ok but to not take them. I reiterated to him that i wasnt angry, that he wasnt in trouble and that myself and his dad love him more than anything in the world and we want him to feel like he can talk to us about anything, because his happiness and safety is more important to us than anything. It was actually a really bonding chat and by the end of it his tears had dried and he was no longer upset.

I told my husband about it and he saw the funny side, we decided it would be best if i spoke to our son about it alone because we didnt want him to feel ambushed. My husband hasnt brought it up with him because it was a private chat between my son and i, and my son and i havent discussed it again either.

A few days ago i went into my sons cubby house and found some pages he had pulled out of one of his books, specifically of beautiful superhero women in powerful poses, that he had displayed on his wall. I can see the funny side of it because what guy hasnt had pictures of beautiful women on their walls in their youth, but part of me also worries that this behaviour is odd for his age. I spoke to him about it in the sense that i asked him not to tear pages out of his books because it damages them, but i didnt address the nature of the pictures.

So tonight out of curiosity i checked the bottom drawer again, i found the book, the torn out pages and a pair of my knickers. Im very confused, moreso because i asked him not to hide my things and he agreed not to. But also, should i be worried about the nature of what hes been hiding? Is this normal behaviour for a boy his age? I really dont want to read into this too far, i dont know whether its just a matter of him making a collection of things he finds pretty or whether he's having identity issues (which im really not sure of as hes so young and honestly there isnt any other thing that stands out, plus even if that were the case it would change nothing about the way we feel about him, we love him unconditionally).

I guess im just asking has anyone else dealt with anything like this? Is this behaviour something we should be worried about? And how should i broach this subject with him because even putting aside what it is that hes taken, he needs to understand that its not ok to take things that dont belong to you.

I feel like im in so far over my head, please help