It took years of dating, dysfunctional relationships and one failed marriage for me to finally find my husband. We have had some tough times, almost split up twice, but we stuck it out and we are SOOOO glad we did because we are very much in love and best friends besides. I would like us to find another couple to have a quad - he is open to it but not the kind to actively seek it.
I guess my point is, I do not expect expanding our relationship and forming new ones to be any easier - but in fact harder. More people, more personalities. But I am not giving up because I think if and when we do find them it will be wonderful! And worth it!