Cleaning lady flash

My girlfriend was at work and i was home early. I rented a top floor apartment at the time and she would call by on her way home.
This day i was incredibly horny so i was texting her at work letting her know, and what I'd like to do with her when she called.
She was getting aroused too so played along. She told me to be naked when i answered the door, no problem.
The teasing continued until she made the made dash for home.
I waited and planned to swing open the door with an erection ready for her.
20 mins later there was a knock on the door, she was always forgetting her key so it wasn't unusual.
I swung the door open, naked with an full hard on to face the cleaning ladies mopping the landing! She had obviously knocked the door with her mop.
Shocked and embarrassed i apologised and started to close the door again as my gf arrived on the scene.
Laughing she told the ladies that "that" was obviously meant for her as she walked in the apartment. Without another word she dropped to her knees and took me in her mouth before I could fully close the door.