Polyamory is the belief that you can be in love, in a relationship, or intimate in your own way with more than one person at once. As a form of ethical nonmonogamy, it is based on fairness, ethics, communication, and honesty.
As parents can love more than one child, we believe that romantic love can be shared with multiple people. Developing feelings for more than one person is natural for many people, and as something which is natural to us, we embrace it and celebrate it.
There are many ways that non-monogamous individuals practice this. Some people prefer to have a partner that they spend most of their time with, sometimes called a "primary" partner. Some people prefer not to have a heirarchical structure. Some develop an interlinked loving relationship that is shared between three or more people who all care about each other.
Poly people do sometimes have issues with jealousy, but we also experience compersion. This is the opposite of jealousy; the positive feeling that we get when we see our partners genuinely happy with someone else. We deal with jealousy through honest and open communication which in turn makes our relationships stronger.
As with all human relationships, communication is incredibly important. Honest expression of feelings and sometimes negotiation of boundaries helps people to feel safe, secure, listened to, and important.
One of the common questions poly people get asked is "Are you swingers?". If it isn't obvious by now, having polyamorous relationships is not just about sex.
Also, we aren't a bunch of cultists preaching against the practice of monogamy. Monogamy works for some people, and for some it doesn't. We accept and are tolerant of both practices and only ask that people are tolerant of ours.
Finally, poly in the UK is very forward-thinking and accepting. The community believes very strongly in complete freedom of sexuality, gender, and identity and is comprised of many LGBT+ people and allies. Sexism, misogyny, and bigotry are not welcome.