Fell into it
My wife and I just fell into polyamory. Our friend moved in with us and we both fell in love with her. My wife and I still have a strong loving relationship. We compared it to having our kids. After the first one I thought I could not love another child, but when number two came along, it hit me. Oh this is how it is. When our partner became a partner, it was eye opening. There are things my wife and her like that I do not like, but there are things that our partner likes that my wife wants nothing to do with. The three of us share a bed every night, and it's been amazing thus far. Monogamy is not for everyone we are discovering. It's been the most amazing time and I wish more people would understand this life style.