To me, it sounds like you are searching for a relationship more on the swinger level. Physical interaction - yes, emotional attachment - no. That is possible for some but not all. But if you search for love and want to plan in advance who is going to fall for whom ... that will be a recipe for drama. You can't plan emotions and feelings. Search a bit for traid, unicorn or boundaries around here. There are many experiences and problem related stories. Maybe you will get something out of them.
Facts: 30, female, bi, v-type relationship with Sward (husband, straight, mono) and Lin (boyfriend, straight, mono), poly-fi and co-primary.