My girlfriend (37) and I (48) have been together for 18 months. We have a great sex life with lots of fun variety like toys, porn, restraints, etc. We have an honest and loving relationship. I have been consistently fantasizing about watching or sharing her with other men, either in a MFM or a Stag/Vixen lifestyle. Before we met, she was promiscuous and I love hearing about her sexy stories and hook ups. She has little to no desire to include other men in our relationship, but she entertains my fantasies. I think my fantasies stem from a number of sources, 1) the desire to see her pleased fully by a male who "better" than me (taller, more endowed), 2) the idea of her being a seductress and a ravenous slut, but then returning to me, and 3) the desire to watch her "in action" whether it's in person or on a video; my own personal porn star.

Thoughts? I'm a bit afraid to explore further and so is she, lest jealousy or something unforeseen negatively affect our relationship.

Any advice would be appreciated.