The first time I got into sharing was with an old girlfriend with my best friend. I wasn't into porn then and never really did much comparison of cock sizes or anything. She was my first and only at that time. I pitched the idea to my friend who was eagerly on board with the idea. He said we would just switch partners. I got a hotel room and we all hung out and did some drinking. we ended up playing some truth or dare. The girls were not aware of our plan. we ended up daring the girls to take their clothes off which then did. Later my girlfriend had to go to the bathroom to pee. I went in there with the door open took out my cock for her to suck. I called my buddy over so he could watch. He walked in out of sight from his girl. He pulled his cock out and to my amazement was much larger than mine. He walked right in front of my girl and she (without hesitation) stopped sucking mine and started sucking his. The happened for just a moment and then we went back to the table where we were all sitting. My buddy and my girl were apparently playing footsies under the table. We then brought the idea to the girls that we would try switching partners. they were game. Things started up. His girl didn't shave which was a bit of a turn off for me, but I tried giving it my all. She was also not into it. I could tell she was disappointed with how much smaller I was compared to him. My girlfriend on the other hand was very excited. She was riding the mess out of him. Moaning and toes curled up. She never did that for me before. Then again I was never able to make her cum and he was not having any problems with that. When he started fucking her in missionary position she reached her hands around digging her fingers into his ass cheeks, moaning and cumming several times. His girl started sucking my cock. She was turned on watching them fuck. His girl then started talking so dirty. His girl said to mine "You like his big cock don't you.", "You wish you can fuck my man all the time.", "Is this the best sex you ever had?" (the response was yes to all) She then said to her man "Cum inside her while I suck on this tinny dick". I almost came when she said that. He start fucking her harder and harder as my girl got louder and louder. no doubt any one near our room would've heard her. Finally he started cumming which triggered her to cum again. He thrusted hard and deep into her as he filled her up. I started cumming but she made me cum on myself. My girlfriend lied still, glowing and smiling. She had the best time ever. He then went back to his girl and fucked her to climax. My girl just stared at him while she touched herself. Watching him fuck his girlfriend probably picturing herself.

That was the first sharing experience. We did have him over to fuck her a few more times after that but his girlfriend did not come.