Fixed error on mechrape, improved pregnancy approach interaction selection logic

1.4/Source/Modules/Interactions/Rules/PartPreferenceRules/Implementation/PregnancyApproachPartKindUsageRule.cs

@@ -24,15 +24,20 @@ namespace rjw.Modules.Interactions.Rules.PartKindUsageRules.Implementation
 
         public IEnumerable<Weighted<LewdablePartKind>> ModifiersForEither(InteractionPawn OwO, InteractionPawn UwU)
         {
-            float weight = OwO.Pawn.relations.GetPregnancyApproachForPartner(UwU.Pawn).GetPregnancyChanceFactor();
-            if (UwU.Parts.Penises.Any())
+            if (OwO.Pawn.relations == null || UwU.Pawn.relations == null)
             {
-                yield return new Weighted<LewdablePartKind>(weight, LewdablePartKind.Vagina);
+                yield break;
             }
-            if (UwU.Parts.Vaginas.Any())
+
+            float weight = OwO.Pawn.relations.GetPregnancyApproachForPartner(UwU.Pawn).GetPregnancyChanceFactor();
+            if (OwO.Parts.Vaginas.Any() && UwU.Parts.Penises.Any())
             {
                 yield return new Weighted<LewdablePartKind>(weight, LewdablePartKind.Penis);
             }
+            if (OwO.Parts.Penises.Any() && UwU.Parts.Vaginas.Any())
+            {
+                yield return new Weighted<LewdablePartKind>(weight, LewdablePartKind.Vagina);
+            }
         }
 	}
 }
\ No newline at end of file