Under their Partners, press What are you trying to fix? and choose the option saying they were never a couple and only share children. Modern families come in all shapes! The child stays joined to both parents – no wedding bells, and no couple line between the parents. For example, if your brother and his son's mum were never together, his son shows with both of them, and nobody's story is told wrongly.
Where to find it
Person page (Safe edit on) → under Parents, Partners or Children → What are you trying to fix?
Only people with the "Add people" and "Remove" ticks, with Safe edit on.
Still stuck? Talk to a real person: send us a message, or email support@mywholefamilytree.com