Difficult subjects

I watched a show the other day about people who used a sperm donor to have a child.  Within the last 10 years the sperm donor companies have a website to have the children and sperm donors register, if they choose to.  It followed one sperm donor, and children who was conceived by sperm donors.  The one gentleman registered not thinking it would really affect him that he would only have a couple children and ended up having over 70 kids that are registered, he could have many more that did not register.  The children that they followed thought it was really nice because they found out that they had siblings and wanted to meet them and start a relationship with them.  The gentleman now has a fiance and a dilema of what to do about the situation because it worries her and makes her feel really apprehensive about getting married.