diff --git a/litellm/responses/utils.py b/litellm/responses/utils.py
index c6912ed977f..4d060836e3b 100644
--- a/litellm/responses/utils.py
+++ b/litellm/responses/utils.py
@@ -231,32 +231,31 @@ class ResponsesAPIRequestUtils:
             )
             non_default_params["previous_response_id"] = decoded_previous_response_id
 
-        litellm_metadata = params.get("litellm_metadata")
-        if not isinstance(litellm_metadata, dict):
-            litellm_metadata = {}
+        litellm_metadata_raw = params.get("litellm_metadata")
+        litellm_metadata: Final = litellm_metadata_raw if isinstance(litellm_metadata_raw, dict) else {}
 
-        requester_metadata = litellm_metadata.get("requester_metadata")
+        proxy_requester_metadata = litellm_metadata.get("requester_metadata")
         metadata_in_params = non_default_params.get("metadata")
-        is_proxy_internal_metadata = any(key.startswith("user_api_key_") for key in litellm_metadata)
+        is_proxy_internal_metadata: Final = any(key.startswith("user_api_key_") for key in litellm_metadata)
 
         metadata_source: dict | None = None
-        if isinstance(requester_metadata, dict):
-            metadata_source = requester_metadata
+        if isinstance(proxy_requester_metadata, dict):
+            metadata_source = proxy_requester_metadata
         elif not is_proxy_internal_metadata and isinstance(metadata_in_params, dict):
             metadata_source = metadata_in_params
 
-        if metadata_source is not None:
-            from litellm.utils import get_requester_metadata
+        from litellm.utils import add_openai_metadata
 
-            converted_metadata: Final = get_requester_metadata(metadata_source)
-            if converted_metadata:
-                non_default_params["metadata"] = converted_metadata
-            else:
-                non_default_params.pop("metadata", None)
-        else:
-            non_default_params.pop("metadata", None)
+        converted_metadata: Final = (
+            add_openai_metadata(metadata_source) if metadata_source is not None else None
+        )
+        non_default_params_with_metadata: Final = (
+            {**non_default_params, "metadata": converted_metadata}
+            if converted_metadata
+            else {key: value for key, value in non_default_params.items() if key != "metadata"}
+        )
 
-        return cast(ResponsesAPIOptionalRequestParams, non_default_params)
+        return cast(ResponsesAPIOptionalRequestParams, non_default_params_with_metadata)
 
     # fmt: off
     @overload
diff --git a/tests/test_litellm/responses/test_responses_utils.py b/tests/test_litellm/responses/test_responses_utils.py
index fa8c351d184..8f2724688ad 100644
--- a/tests/test_litellm/responses/test_responses_utils.py
+++ b/tests/test_litellm/responses/test_responses_utils.py
@@ -185,6 +185,34 @@ class TestResponsesAPIRequestUtils:
         )
         assert result["metadata"] == {"customer_id": "cust-456"}
 
+    def test_get_requested_response_api_optional_param_preserves_sibling_metadata_keys(self):
+        result = ResponsesAPIRequestUtils.get_requested_response_api_optional_param(
+            {
+                "temperature": 0.7,
+                "metadata": {
+                    "customer_id": "cust-123",
+                    "requester_metadata": {"nested": "value"},
+                },
+            }
+        )
+        assert result["metadata"] == {"customer_id": "cust-123"}
+
+    def test_get_requested_response_api_optional_param_proxy_snapshot_no_double_unwrap(self):
+        result = ResponsesAPIRequestUtils.get_requested_response_api_optional_param(
+            {
+                "temperature": 0.7,
+                "metadata": {"model_group": "test-model"},
+                "litellm_metadata": {
+                    "requester_metadata": {
+                        "customer_id": "cust-789",
+                        "requester_metadata": {"nested": "value"},
+                    },
+                    "user_api_key_team_id": "team-1",
+                },
+            }
+        )
+        assert result["metadata"] == {"customer_id": "cust-789"}
+
     def test_decode_previous_response_id_to_original_previous_response_id(self):
         """Test decoding a LiteLLM encoded previous_response_id to the original previous_response_id"""
         # Setup