I feel like you should talk to your partner about sexual fantasies in general because of your hypersexuality and your promiscuous past. It seems like there are things you wish you could do with him that you haven't, things that are generally part of the "porn world" sex. It seems like you want to explore more hardcore, or more experimental, sex with him.

Those desires may be manifesting in a sexual fantasy about his friend. Maybe subconsciously you think his friend can perform those "porn world" acts with you whereas you don't think your partner can. Maybe you want to engage in "slutty" sexual acts that you feel like your partner may look down on. I honestly don't know. And I don't know the extent of you and your partner's sexual relationship, but if you haven't already, I think you should open up to him about your "porn world" sexual desires and fantasies (not about his friend specifically) and see how that makes you feel.