diff --git a/src/npc/newSlaveIncestSex.tw b/src/npc/newSlaveIncestSex.tw
index b9ee580c469dea19456e1bc90077e1659ef57d45..ce5b4a75e51e381db07355533f4047dd65efc420 100644
--- a/src/npc/newSlaveIncestSex.tw
+++ b/src/npc/newSlaveIncestSex.tw
@@ -68,7 +68,7 @@
 		/* Note: this is never true (at least without extended family mode) */
 		<<set _onelong = "younger "+_one >>
 		<<set _otherlong = "older "+_other >>
-	<<else>> /* twins, no real differentiation */
+	<<elseif $familyTesting != 1>> /* twins, no real differentiation */
 		<<if $relative.vagina == -1 && _one != "brother">>
 			<<set _onelong = _one + " brother">>
 		<<elseif _one != "sister">>