My boss is screwing the best office girl

This is a small story that I'm sharing with you, I hope you like it, and if you help me improve, I'll greatly appreciate it, well, here it is.

We worked in a province, we were an electrical installation company, the staff was very few, actually only 4 people in administration, my boss, two secretaries and me, one of them was beautiful, tall, with white skin, black hair, long legs, a good ass, but the best were her tits, divine, big that made you lose your head. Finally, our offices were a complete house rented by the owner, three bedrooms that adapted as offices and storage room, the dining room and living room adapted as reception and two desks for administrators, in the living room there was a window that gave onto another storage room, which was not part of the house, finally our boss was an old man between 45 and 50 years old, tall, with very dark skin and ugly haha.

One day the second secretary didn't come to work, and I had to take care of field matters so I left the office and went to the construction site, which would take at least half the day, to get to the construction site you had to take a bus, I left the office and went to wait for the bus at the stop, halfway there I remembered that I had forgotten some documents and had to go back for them, so I returned to the office, when I was arriving I heard many laughs and decided to enter the storage room through the window to see what was going on, which was my surprise to see the old man kissing the beautiful secretary, he was caressing her tits and ass, and she was rubbing his cock over his pants, then he lowered his pants and pushed her against the wall and started sucking her pussy, she was twisting with pleasure, I was dying of envy, seeing that old man suck her delicious ass and she enjoying it, she was massaging her tits from the pleasure she felt, and took off her blouse and bra to leave her beautiful tits in the air, the old man stood up and started grabbing her tits while she tried to get his cock out of his pants, she got it out and started caressing it with her hands, when it got harder she turned around and knelt down to suck that black cock, it was very big, she looked at it. While she was sucking that cock in her mouth and started to suck it with her beautiful mouth, she sucked and swallowed everything she could, the old man was really enjoying himself and pushed his cock harder, she left herself all wet and stood up, turned around and grabbed that cock and put it in the door of her pussy, the old man slammed it all in one go and a big loud moan came out of her, then he continued with short but strong thrusts and she only screamed with pleasure, after that he gave it to her faster and she asked for more, screaming like a real slut, his moans could be heard throughout the office, and the old man gave it to her harder, she was holding onto the wall from all the thrusts he was giving her, they kept going until he pulled his cock out of her pussy and turned her around, she knew it was time to take her cum, she put that black cock in her mouth and started sucking like crazy, he pulled the cock out of her mouth and gave her a big load of cum on her face and tits, she took as much as she could and kept sucking that cock until it was clean, she cleaned up the cum from her tits and brought it to her mouth, got up and went to the bathroom to clean her beautiful face, I left quickly so they wouldn't catch me, returned to work and in the afternoon saw them very happy together, I knew why they had had a great sex session that morning and was sure it would happen again, and from that day on I entered the office with more caution to see if I could find them again.