Captain Jack Harkness is notorious for being attracted to any gender of any species at any time.
While it can be good to see the best in others, sometimes one must still set standards. Relationships are both in the now and what we hope for the future of the partnership. If we can't bring ourselves to be selective in our choices, we won't be selective in our treatment of those important to us. Being selective of who we choose for our partner is part of how we value ourselves. If we don't treat ourselves right, how will we know when we're treating others well?
Happy Belated Halloween, everyone!