Generally I feel whatever floats your boat. I always believed in one on one relationships until I found myself in love with two very different men. I mean real love not just one for sex and another for bringing home the bacon. It's best not to judge because many factors are involved. I have always believed you could love more than one person in life just didn't think it would happen to me.

I wouldn't be mad at your friend who suggested it to you as I'm sure they meant it with good intentions. It's your choice not to go outside the marriage and if you are fine with the way things are then hold onto your beliefs. Congrats on your children, they are a gift!