There certainly seems there could be exploratory desires in his chart as well but you have to be careful since he/you have to manage the sensitive piscean nature that he has... which could manifest a variety of ways. His internal struggle is probably trying to balance his fiery and watery natures.
So true. In his chart, mercury in pisces is me, his wife. Venus (women and how he loves) is also venus. So I see this as portraying the submissive, vulnerable side to love and sex. So that would be me. He is Jupiter in cancer, so he is sensitive to me during sex. His 5th ruler is same as mine - Neptune in sag. But as for poly type of relationships id probably look at Uranus and he trines Uranus and venus trines Uranus too, but im not sure if that's enough.