Just came natural to us. We used to tell each other about our previous lovers. She once told me that she'd love to fuck an old friend again so we set it up. That was a night to remember.
Back in the day I left my porn out. After I read a story about watching a wife being fucked by an old friend of hers, I fucked her hard then eat her out then fucked her angain. She asked what had gotten in to me I showed her the story and told her I fantasize about her being with one one her boyfriends. Over a few years of telling her my fantasies and asking her to tell me about what turned her on and what were her fantasies, she finally fucked a friend then cam home and told me all about it while I eat her out. After awhile we ended up having weekend parties that were free for alls.