I think I know what you're referring to.
This could be the result of having someone with more than two relationships. Lines represent relationships. Their partner will be on one side of them connected by a line. If they have two partners, one will be on each side. If they have three, they've run out of sides and two partners will have to be next to each other. So one partner will be further away from that first someone. But a line still needs to get to them. Imagine a line going behind the box of the partner right next to them. This looks like two lines, but really, it's one line going to each partner.
I hope this makes sense.