diff --git a/README.md b/README.md
index 5c3ebf6..48d2deb 100644
--- a/README.md
+++ b/README.md
@@ -79,6 +79,7 @@ Windows route-table boundary:
 - scoped default-route suppression with restore-on-drop behavior
 - unicast IP address snapshots for TAP diagnostics
 - scoped host-route pinning for the relay IP on the pre-TAP interface
+- reuse of an already-existing matching relay host route without deleting it on exit
 - non-Windows builds return a clear unsupported-platform error
 
 ### `lanparty-client-tap`
@@ -214,8 +215,9 @@ bridges Ethernet frames between the relay and the first TAP-Windows6 adapter
 until shutdown. `--relay` accepts a DNS name or socket address; bare hosts
 default to UDP/443. Before opening the adapter, it writes the
 generated tunnel MAC to the TAP driver's `NetworkAddress` registry setting.
-The startup status reports whether the relay already has a LAN gateway for the
-room.
+If the exact relay host route already exists, the client uses it and leaves it
+alone on exit. The startup status reports whether the relay already has a LAN
+gateway for the room.
 `--virtual-mac` can still override the stored identity for manual testing. On
 Windows it sets the TAP IP interface MTU to the relay-selected MTU, marks the
 TAP media connected for the scoped client run, and reports the driver MAC/MTU
diff --git a/TESTING.md b/TESTING.md
index d2982f2..b4bc4bc 100644
--- a/TESTING.md
+++ b/TESTING.md
@@ -125,6 +125,10 @@ TAP driver reports MAC ... and MTU ...
 client diagnostics: relay reachable yes gateway connected yes route pinned yes ...
 ```
 
+The route pin line ends with `(created)` or `(already existed)`. Either is OK.
+`already existed` usually means a matching relay host route was already present,
+for example after a previous crashed test run.
+
 The first diagnostics line may show `IP unknown`. After DHCP succeeds, a later
 line should show:
 
@@ -231,8 +235,9 @@ Uncommon LAN subnets such as `10.73.42.0/24` are safer than `192.168.0.0/24`.
 
 ## Cleanup
 
-Stop client, gateway, and relay with Ctrl-C. The Windows client restores the TAP
-route policy and marks TAP media disconnected when it exits normally.
+Stop client, gateway, and relay with Ctrl-C. The Windows client removes the
+relay host route only when it created that route itself, restores the TAP route
+policy, and marks TAP media disconnected when it exits normally.
 
 Keep `lanparty-client-identity.json` if you want the same virtual MAC on the
 next run. Delete it only when you intentionally want a new client identity.
diff --git a/crates/lanparty-client-route/src/windows.rs b/crates/lanparty-client-route/src/windows.rs
index ae26b53..67a72f1 100644
--- a/crates/lanparty-client-route/src/windows.rs
+++ b/crates/lanparty-client-route/src/windows.rs
@@ -7,7 +7,7 @@ use std::{
 
 use anyhow::{Context, Result, bail};
 use windows_sys::Win32::{
-    Foundation::ERROR_SUCCESS,
+    Foundation::{ERROR_OBJECT_ALREADY_EXISTS, ERROR_SUCCESS},
     NetworkManagement::{
         IpHelper::{
             ConvertInterfaceGuidToLuid, ConvertInterfaceLuidToIndex, CreateIpForwardEntry2,
@@ -439,25 +439,39 @@ pub fn pin_relay_route(route: &RouteSnapshot) -> Result<PinnedRelayRoute> {
         // valid host destination, next hop, and interface identity.
         CreateIpForwardEntry2(&pinned.row)
     };
-    windows_status(status).with_context(|| {
+    let disposition = route_create_disposition(status).with_context(|| {
         format!(
             "failed to pin relay route to {} via interface index {}",
             route.destination(),
             route.interface_index()
         )
     })?;
-    pinned.active = true;
+    pinned.delete_on_drop = disposition == RouteCreateDisposition::Created;
 
     Ok(pinned)
 }
 
+#[derive(Debug, Clone, Copy, PartialEq, Eq)]
+enum RouteCreateDisposition {
+    Created,
+    AlreadyExists,
+}
+
+fn route_create_disposition(status: u32) -> io::Result<RouteCreateDisposition> {
+    match status {
+        ERROR_SUCCESS => Ok(RouteCreateDisposition::Created),
+        ERROR_OBJECT_ALREADY_EXISTS => Ok(RouteCreateDisposition::AlreadyExists),
+        _ => Err(io::Error::from_raw_os_error(status as i32)),
+    }
+}
+
 pub struct PinnedRelayRoute {
     row: MIB_IPFORWARD_ROW2,
     destination: IpAddr,
     next_hop: Option<IpAddr>,
     interface_index: u32,
     interface_luid: u64,
-    active: bool,
+    delete_on_drop: bool,
 }
 
 impl PinnedRelayRoute {
@@ -480,6 +494,11 @@ impl PinnedRelayRoute {
     pub const fn interface_luid(&self) -> u64 {
         self.interface_luid
     }
+
+    #[must_use]
+    pub const fn created_by_client(&self) -> bool {
+        self.delete_on_drop
+    }
 }
 
 impl fmt::Debug for PinnedRelayRoute {
@@ -489,14 +508,14 @@ impl fmt::Debug for PinnedRelayRoute {
             .field("next_hop", &self.next_hop)
             .field("interface_index", &self.interface_index)
             .field("interface_luid", &self.interface_luid)
-            .field("active", &self.active)
+            .field("delete_on_drop", &self.delete_on_drop)
             .finish_non_exhaustive()
     }
 }
 
 impl Drop for PinnedRelayRoute {
     fn drop(&mut self) {
-        if !self.active {
+        if !self.delete_on_drop {
             return;
         }
 
@@ -532,7 +551,7 @@ fn pinned_route_row(route: &RouteSnapshot) -> PinnedRelayRoute {
         next_hop,
         interface_index: route.interface_index(),
         interface_luid: route.interface_luid(),
-        active: false,
+        delete_on_drop: false,
     }
 }
 
@@ -685,6 +704,22 @@ mod tests {
         assert_eq!(pinned.row.SitePrefixLength, 32);
         assert_eq!(pinned.row.Metric, 0);
         assert_eq!(pinned.row.Protocol, RouteProtocolNetMgmt);
+        assert!(!pinned.created_by_client());
+    }
+
+    #[test]
+    fn classifies_route_create_statuses() {
+        use windows_sys::Win32::Foundation::ERROR_INVALID_PARAMETER;
+
+        assert_eq!(
+            route_create_disposition(ERROR_SUCCESS).unwrap(),
+            RouteCreateDisposition::Created
+        );
+        assert_eq!(
+            route_create_disposition(ERROR_OBJECT_ALREADY_EXISTS).unwrap(),
+            RouteCreateDisposition::AlreadyExists
+        );
+        assert!(route_create_disposition(ERROR_INVALID_PARAMETER).is_err());
     }
 
     #[test]
diff --git a/crates/lanparty-client-win/src/main.rs b/crates/lanparty-client-win/src/main.rs
index 0fcf4c7..a89ea13 100644
--- a/crates/lanparty-client-win/src/main.rs
+++ b/crates/lanparty-client-win/src/main.rs
@@ -332,13 +332,18 @@ fn print_relay_route(route: &RouteSnapshot) {
 #[cfg(windows)]
 fn print_pinned_relay_route(route: &PinnedRelayRoute) {
     println!(
-        "relay route pinned before TAP: destination {} next hop {} interface index {} LUID {}",
+        "relay route pinned before TAP: destination {} next hop {} interface index {} LUID {} ({})",
         route.destination(),
         route
             .next_hop()
             .map_or_else(|| "on-link".to_string(), |next_hop| next_hop.to_string()),
         route.interface_index(),
-        route.interface_luid()
+        route.interface_luid(),
+        if route.created_by_client() {
+            "created"
+        } else {
+            "already existed"
+        }
     );
 }