Do not pass over the `session` argument to `Session.request` method
diff --git a/requests/api.py b/requests/api.py
index 8ff22e7baa..40966cf350 100644
--- a/requests/api.py
+++ b/requests/api.py
@@ -34,7 +34,7 @@ def request(method, url, **kwargs):
     :param verify: (optional) if ``True``, the SSL cert will be verified. A CA_BUNDLE path can also be provided.
     """
 
-    s = kwargs.get('session') or sessions.session()
+    s = kwargs.pop('session') if 'session' in kwargs else sessions.session()
     return s.request(method=method, url=url, **kwargs)
 
 

The `request` method of `Session` class does not take a `session` argument. But `api.request` does. So, it has to be popped before you can send the whole `kwargs` dict to `Session.request` method.
