Sebastian Kedracki was fired after he was 'caught red handed' partying with the woman at the end of a shift.
It was heard that one colleague spotted them 'dancing' round the office surrounded by bottles before they went to a pub and returned to one of Club Quarters Hotel's luxurious rooms.
The tribunal heard that at around 3am, one guest staying in the building, in Covent Garden, complained that she could hear 'loud music' and that her husband couldn't sleep.
Colleagues used a master key to enter the room and found the couple in the shower together and then on the bed, the hearing was told.
The senior employee was suspended over the matter and faced disciplinary proceedings which resulted in his sacking.
He took the hotel to an employment tribunal, claiming there had been a 'witch hunt' against him, and his claims of unfair dismissal were upheld due to faults in the investigation.
But, a judge ruled that Mr Kedracki should receive no compensation as his bosses were right to sack him.
The tribunal, held in central London, was told Mr Kedracki started working at the Club Quarters Hotel in Covent Garden in 2013.
The building overlooks Lincoln Inn Fields and is located near Royal Opera House and the British Museum.
It costs between £200 and £300 per person to stay overnight.
During the Covid pandemic, he stayed in the hotel frequently, including a period of 18 months when he had no other accommodation.
But, this stopped in September 2021, as guests staying in the hotel were picking up again following a lull due to the pandemic.
In May 2021, he was promoted to Senior Guest Experience Manager.
The panel heard that there were issues between Mr Kedracki and one of his managers as he refused to wear the suit jacket which is part of his uniform.
It was heard Mr Kedracki found it 'too hot' to wear the item of clothing.
He was handed a formal warning for the 'continuous breaking of hotel policy', and for 'poor team leadership', relating to his failure to challenging colleagues not wearing a mask.
The panel heard that Mr Kedracki faced further disciplinary action in relation to an incident which took place on December 29, 2022.
It was heard that Mr Kedracki had been 'drinking and intoxicated' with a junior female colleague in his office.
It was heard they later stayed overnight in room 115 without permission and were playing very loud music which disturbed a guest between 3am and 4am in the morning.
Mr Kedracki was suspended on January 17, 2023 over the incident and an investigation was held.
A witness to the incident said that he overheard music playing from the back office at 11:30pm, commenting that it sounded 'like a disco club with the volume on maximum'.
He said he went to speak to Mr Kedracki and the woman to tell them the music was too loud but the doors were locked.
It was heard the woman could be seen dancing, the lights were switched off, and there were several bottles of alcohol around.
He said that at around 3:40am, a guest from another room complained and said she could hear very loud music which meant her husband cannot sleep.
Another colleague was reportedly sent to investigate and said that when he went into the room, he said he could hear 'very noisy music like a discotheque' and opened the door to find Mr Kedracki and the woman together in the shower.