I've operated under the Michael Stipe concept of sexuality. "What you do with your junk is none of my business unless one of us is sitting in the other person's lap"
Beyond that, if it's consensual, I don't care. My only concern with pansexuality, and large lover groups, is that it seems to increase the amount of relationship drama exponentially. I've known a few people who were pansexual, and were in a multi-person relationship, and the group dynamics never gelled 100%. She really liked Guy A, but Guy B was someone she liked, but not LIKED liked. She also was civil around Girl B, but they didn't agree on a lot of things, so they would tend to get on each others nerves, which would bother Guy A, because he really liked Girl B, and this caused Girl A to get upset, which would upset Guy B, etc etc. Not saying this is a certain thing, but every relationship has it's problems, and with more people, you get more problems. Beyond that aspect being a concern I see, fuck whoever you want, I don't care. Have fun, stay hydrated, and the safe word is snuffalupagus