Popup windows for every new connection

Question

Is there a way to popup new window upon new connection using python socketserver and python Gtk?

server.py has the following classes

class Handler(BaseRequestHandler):
    def handle(self):
        ...
        # self.win = ClientWindow(self)
        # GLib.idle_add(self.popup)

    def popup(self):
        self.win = ClientWindow(self)
        return False


class Server(ThreadingTCPServer, ThreadingMixIn):
    allow_reuse_address = True

window.py

class ClientWindow(Gtk.Window):
    def __init__(self, con):
        super().__init__(title=f"{con.client_address[0]}:{con.client_address[1]}")
        self.set_default_size(500, 500)
        self.connect("destroy", self.close_window)
        self.con = con
        self.show_all()
    
    def close_window(self):
        self.hide()

The goal is to server the client connection from the window.

I tried using GLib.idle_add in Handler class to pop up the new window but the socket file descriptor is -1 meaning the connection is already closed.

Another approach was to create the client window in the handle method in Handler class but this also does not work.