"Yeah, we're sisters."

Children of the same sperm donor find each other and build their relationship. If you were a sperm donor, originally intent on remaining out of the picture, but you knew that a large group of your children had sought each other out and formed powerful love bonds, would you have a change of heart? What if there were dozens of your kids out there, and they all got together and started to see themselves as a big family, with you as an absent presence? Would it make you sad? Would it make you lonely?

[Two half-sisters] are considering a trip to Wilmington, Del., which Donor 150 listed as his birthplace.

Hey, maybe it's my brother. I could be your aunt. When do I get in on this extended family action?