I don't consider me especially big at 18cm and about 16 around. I used to travel for vacation and been many times to massage, mostly with a guy. It sometimes happen when they massage down there that I start to grow and the guy say wow, or big big! One guy I know since some years when he first put his hand down my underwear look me in the eye and say OH! We go to room, because he wanted to play with it. After he used to call me anaconda. He had a very nice cock too, but smaller.
Once I sit in a bar where I know the lady owner. Once se told me "that girl would like to go with you". OK, we talked a bit and agree to go to room. She was young, but LEGAL! When she played with me and I started to grow, she said it's soo big! I prepared her and she was very wet and ready. Then when I was to enter her she said easy, it's so big. She was so tight and wet but I easily slide in. She was nice and tight and felt good and not long before she started to moan and soon she orgasmed and then I couldn't hold back and shoot a big load in her. Another time in a "no sex" massage the guy made it good and I couldn't help but get hard. He looked at me and whisper "you have so nice big cock" and then surprised me by giving me a happy ending!
Maybe I'm just over average, but nothing special I think. Maybe too many details, hope OK?