hotfix `$pc.sexStatistic()`

sugarcube/src/playerCharacter/PlayerCharacter.ts

@@ -1671,14 +1671,14 @@ class PlayerCharacter implements Character{
 				activity = [activity];
 
 			if(!familiarity)
-				familiarity = Object.keys(Object.values(this._sexStatistics)[0]) as ESexEncounterFamiliarity[];
+				familiarity = [ESexEncounterFamiliarity.ACQUAINTANCE,ESexEncounterFamiliarity.FRIEND,ESexEncounterFamiliarity.LOVE,ESexEncounterFamiliarity.STRANGER];
 			else if(!Array.isArray(familiarity))
 				familiarity = [familiarity];
 
 			for(const activityKey of activity){
-				const activityData:SexStatistic = this._sexStatistics[activityKey];
+				const activityData:SexStatistic = this._sexStatistics[activityKey] ?? {};
 				for(const familiarityKey of familiarity){
-					const familiarityData = activityData[familiarityKey];
+					const familiarityData = activityData[familiarityKey] ?? [0,0];
 					switch(awareness){
 						case "aware":	result += familiarityData[0]; continue;
 						case "unaware":	result += familiarityData[1]; continue;