Dustmite, I love the idea in theory. I think it would be exciting to not know how things are going to turn out. And I love the whole "putting your faith in fate" idea. Also I love the idea of lots of kids and lots of love.
Practically it wouldn't work for us, but if it would for you I say go for it. It's not like you don't know what to expect, you already have 3 kids and two are close together, so you've BTDT. You know how hard it is, so you are going in with your eyes open.
Bookmarks