Tied tits/Partial fisting

She was house sitting, so no one could hear her scream when she came multiple times as she always does. She wanted me to show her the ropes, so I did. I believe that I tied her left breast a little too tightly and left some marks, which you can see in one of the images. We are working on fisting as well, she really wants to experience it, both vaginally and anally. She's asked me about a gang bang as well, though she's kinda shy, so who knows if it is a fantasy or a requirement.