As a student I lived in a shared flat with a hot friend of mine. She was about 5'6'', slim brunette with small but nicely shaped B-cup breasts. I had a crush on her, but we've never been intimate,
We used to hang out together a lot in the evenings (watching films or just chatting). She usually wore her pajamas on those occasions. It consisted of loose shirt and no bra underneath so her nips were obviously clearly visible through the material. I remember my first downblouse which happened just few days after we moved in. I was sitting on her bed and she leaned towards me to close the window that was behind me. Her shirt went down, making her upper parts completely visible from my point of view. However it lasted so short that before I've realized what's happening and focused my eyes in the proper place, it was all over. She was standing in front of me and I was sitting with my jaw dropped open. I think she knew where I was looking, but didn't say anything.
On next occasions I knew where to aim my eyes, so those evenings gave me plenty opportunities to see those beautiful titties under her pajamas. Sometimes it was accidental and sometimes I managed to position myself in proper way and then, for example, pretending to show her something in the book, make her lean forward and expose at least one tit to me. She had beautiful puffy nipples with big aureolas.
I have a strong and vivid memory of one special experience, even though it happened few years ago. I was walking with a cup of coffee from the kitchen and stopped by her room to talk for a while. She was preparing for some party and had just showered., so she had her bathing robe on and probably nothing underneath. She was painting her nails, sitting at her desk and I was casually standing in a doorway, drinking my coffee. I noticed that her robe was a bit more open than it should be and she was showing a lot of cleavage. I started getting aroused and was thinking desperately if I could do something to see more. I made few steps towards her, still continuing casual talk, but unfortunately I didn't manage to see any more flesh. Then, suddenly, my friend turned to me on her chair and asked me to hand her a nail polish that was on the cupboard behind me. As she turned, her robe felt even more open and made her right boob completely uncovered! I reached for the nail polish with shaking hands, growing erection and heart pounding so fast, I was sure she would hear it. But, to my surprise, she was totally oblivious! She just continued to do her nails and I stood there pretending nothing happened. At this time I had no idea what we were talking about. All my attention was on this pretty boob that was on full display to me. It probably lasted for another few minutes and then she excused me and said she need to dress for the party.
I don't need to tell you what I've done just after she left
I am still wondering if she has done it on purpose or was completely unaware of the exposure.