You'll get more responses to queries about trees, if you post in the "Member Tree" Forum.
Here's solve your dilemma with unmarried couples and their children. There isn't an option for same sex couples to date.
1) Add the person as husband or wife as you normally do.
2) Now add their child.
3) Open the "people" record for one of the parents.
4) In that record, open "edit profile"
5) There are tabs near the top of the record. Open the "Relationships" tab.
6) "Remove" any of the unwanted relationships, in your case that would be under the "Spouses"
7) The two people will remain in your tree, but their connection will only show up as parents of the child.