Go in and join them

How could I not go in there? Gina was clearly wanting an extra cock to play with.
Perhaps I should have considered leaving and going home to my wife, but the thought of screwing the sexy as hell young girl outweighed any other considerations. Well, to be honest it didn't so much outweigh them as negate them entirely. I never even considered the consequences, my dick was clearly thinking for me.

I climbed off Gina's desk and pushed the door open, dick in hand.

"Fuck!" Dan swore, attempting to put his dick back in his pants, before noticing mine.
I walked straight over to Gina and simply held my dick in front of her face. She immediately grabbed it, commenting "Good, I hoped you'd come in here... " She looked down at her boss, "Dan what the hell are you doing? Get your dick back in me!" and proceeded to take my cock in her mouth. As she pumped my shaft with one hand she rolled her tongue around my head and sucked deeply. She might be young, but she was a talented fellatrix, that was for sure. As Dan resumed fucking Gina's pussy she reached out with her second hand and began cupping and squeezing my balls as she continued stroking, and her tongue ran all over my head, even attempting to insert itself down my urethra. This was a feeling I could get used to, though I wouldn't be able to enjoy it much longer. My cock was hard and I could feel the familiar rising as my balls were about to release their load. Gina sensed it and massaged my balls even more firmly making me cum immediately.

Gina pulled my dick almost entirely from her mouth, leaving just my head inside as I fired volley after volley of cum into her. She held it all in her mouth rather than swallowing or spitting it out immediately, and swirled it around my cock head. She was still firmly grasping my balls, massaging the last of my cum from them, not allowing me to withdraw. She was eager to drain every last drop from me, and was doing a damn good job of it.

Immediately that she decided she'd finished with me she pushed Dan back with her legs and spun around, taking his dick in her mouth. He moaned as she engulfed him, her cheeks still bulging with my cum. "Oh, fuck girl, you're so good at that," Dan managed to get out before she began squeezing his balls, massaging his cum from them. "Oh, shit yes, suck my dick baby, take my cum!" he yelled as he thrust into her. As he fired his load into her mouth I inserted my fingers into her loose cunt and played inside her. The combined loads from Dan and I were too much and some of our cum spurted from her mouth before she decided to swallow it all. Immediately she wiped the cum from Dan's desk and sucked her finger clean, before taking Dan back into her mouth cleaning him off. When she was done she turned back to me and cleaned my fingers of her juice and my cock of my cum without so much as a word.

She sat back in front of us when she was finished cleaning me, a satisfied smile on her face as she looked at our two no longer hard cocks. Dan and I looked at each other, somewhat nervously now that'd we'd both cum and were able to think straight again. "Umm... I... I should be going," I started to say before Dan stopped me. "Wait. You're not going to tell anyone about this." It wasn't a question. It was clearly a statement. "umm... No... No, of course not." I paused before continuing without thinking. "Neither of our wives would like what happened here."

"That's right!" Gina replied. "I'm already getting what I want from Dan, but as you point out, your wife won't like to hear about this either."
"Oh... what do you want?" I asked
"Well, I don't know yet, other than more of your cock, but I'm sure I'll think of something."
I was a little surprised when she seemingly altruistically continued, "Dan, I think you should give him a raise too, just to encourage him not to say anything."
"Okay," was all he replied, clearly under her control. Perhaps that wasn't such a good sign. She wanted me to know she held both the carrot and the stick. Smart girl.
"Now, both of you get dressed and go home, and when you fuck your wives tonight, think of me."

Both of us complied, dressing silently. It was a very awkward trip to the carpark, trapped in the lift together before we went our separate ways and headed home, with me wondering if I should mention having seen Gina and Dan to my wife, or say nothing at all.