diff --git a/src/pyplaml/diagram_edge.py b/src/pyplaml/diagram_edge.py
index 966e68afced63c8b1e47fe6af7479d744fce3828..afec5c758705976a646974e5a843671dd31df871 100644
--- a/src/pyplaml/diagram_edge.py
+++ b/src/pyplaml/diagram_edge.py
@@ -45,9 +45,14 @@ class DiagramEdge(DiagramObject):
         self.redraw()
 
     def get_dir(self) -> Direction | None:
-        if self.source_rel != Relation.NONE:
+        is_left = self.source_rel != Relation.NONE
+        is_right = self.target_rel != Relation.NONE
+
+        if is_left and is_right:
+            return None
+        if is_left:
             return Direction.LEFT
-        elif self.target_rel != Relation.NONE:
+        elif is_right:
             return Direction.RIGHT
 
         return None