diff --git a/party-stage/src/scene/party-guests.js b/party-stage/src/scene/party-guests.js
index 04d69cf..264a995 100644
--- a/party-stage/src/scene/party-guests.js
+++ b/party-stage/src/scene/party-guests.js
@@ -152,6 +152,21 @@ export class PartyGuests extends SceneFeature {
 
         const time = state.clock.getElapsedTime();
         const minDistance = 0.8; // Minimum distance to maintain
+        const minDistSq = minDistance * minDistance;
+
+        // --- Spatial Grid Optimization ---
+        const cellSize = 2.0;
+        const grid = {};
+        
+        // Populate grid
+        for (let i = 0; i < this.guests.length; i++) {
+            const g = this.guests[i];
+            const cx = Math.floor(g.mesh.position.x / cellSize);
+            const cz = Math.floor(g.mesh.position.z / cellSize);
+            const key = cx + ':' + cz;
+            if (!grid[key]) grid[key] = [];
+            grid[key].push(i);
+        }
         
         this.guests.forEach((guestObj, i) => {
             const { mesh, leftArm, rightArm } = guestObj;
@@ -160,19 +175,31 @@ export class PartyGuests extends SceneFeature {
             let separationX = 0;
             let separationZ = 0;
             
-            for (let j = 0; j < this.guests.length; j++) {
-                if (i === j) continue;
-                const otherMesh = this.guests[j].mesh;
-                
-                const dx = mesh.position.x - otherMesh.position.x;
-                const dz = mesh.position.z - otherMesh.position.z;
-                const distSq = dx*dx + dz*dz;
-                
-                if (distSq < minDistance * minDistance && distSq > 0.0001) {
-                    const dist = Math.sqrt(distSq);
-                    const force = (minDistance - dist) / minDistance; 
-                    separationX += (dx / dist) * force;
-                    separationZ += (dz / dist) * force;
+            const cx = Math.floor(mesh.position.x / cellSize);
+            const cz = Math.floor(mesh.position.z / cellSize);
+
+            for (let ox = -1; ox <= 1; ox++) {
+                for (let oz = -1; oz <= 1; oz++) {
+                    const key = (cx + ox) + ':' + (cz + oz);
+                    const cell = grid[key];
+                    if (!cell) continue;
+
+                    for (let k = 0; k < cell.length; k++) {
+                        const j = cell[k];
+                        if (i === j) continue;
+
+                        const otherMesh = this.guests[j].mesh;
+                        const dx = mesh.position.x - otherMesh.position.x;
+                        const dz = mesh.position.z - otherMesh.position.z;
+                        const distSq = dx*dx + dz*dz;
+                        
+                        if (distSq < minDistSq && distSq > 0.0001) {
+                            const dist = Math.sqrt(distSq);
+                            const force = (minDistance - dist) / minDistance; 
+                            separationX += (dx / dist) * force;
+                            separationZ += (dz / dist) * force;
+                        }
+                    }
                 }
             }