My girlfriend experiments with anal play using a plug

My girlfriend loves to play the game and she did it again when we were alone. She wanted to try anal play with a plug and I was not against it. She laid on the bed and spread her legs, then took out the plug from my friend's ass. I saw her insert it into her ass. At first, she tried to push it into the ass, but it was too difficult. Then, I helped her to push the plug deeper and deeper into the ass. She moaned with pleasure as I pushed the plug further and further into the ass. I could see that she was enjoying the sensation of the plug in the ass. After a while, she took out the plug from the ass and cleaned it. She was very happy with the result and asked me to buy more plugs for her.