diff --git a/src/data/backwardsCompatibility/datatypeCleanup.js b/src/data/backwardsCompatibility/datatypeCleanup.js
index 25f92ba850c43cdeb62058b216ee8d1dee109ecd..47ceb643ef272744699d05cd2e83541c18ad8b92 100644
--- a/src/data/backwardsCompatibility/datatypeCleanup.js
+++ b/src/data/backwardsCompatibility/datatypeCleanup.js
@@ -1351,6 +1351,9 @@ globalThis.PCDatatypeCleanup = function() {
 	if (typeof V.PC.ID === "undefined") {
 		V.PC.ID = -1;
 	}
+	if (typeof V.PC.partners !== "object") {
+		V.PC.partners = new Set();
+	}
 
 	/* None of these are in use */
 	PC.bellyPreg = PC.belly;
diff --git a/src/player/js/PlayerState.js b/src/player/js/PlayerState.js
index 25b76da113b47acca9c5a3b6a5c9d1e381308643..37909030c9ef0ab37613e3559b2a58bc5692b25a 100644
--- a/src/player/js/PlayerState.js
+++ b/src/player/js/PlayerState.js
@@ -1540,6 +1540,25 @@ App.Entity.PlayerState = class PlayerState {
 		 * 0: sated
 		 */
 		this.need = 0;
+		/**
+		 * A list of IDs of anyone the PC has ever slept with.
+		 *
+		 * Only contains unique entries.
+		 *
+		 * | ***ID*** | **Type**               |
+		 * |---------:|:-----------------------|
+		 * | *1+*     | Normal slave		   |
+		 * | *-2*     | Citizen*               |
+		 * | *-3*     | PC's former master*    |
+		 * | *-4*     | Fellow arcology owner* |
+		 * | *-6*     | Societal Elite*        |
+		 * | *-8*     | Animal*                |
+		 * | *-9*     | Futanari Sister*       |
+		 *
+		 * **not currently implemented*
+		 * @type {Set<number>}
+		 */
+		this.partners = new Set();
 		/**
 		 * attraction to women
 		 * * 0 - 5: disgusted by women