And here is my Jack Harkness, River Song and John Hart fic. This is part of my Tiphys Chronicles universe. so River and Jack are already working together:

Of All the Gin Joints in All the Universe – Captain John Hart swanning into Jack’s life always makes things more interesting.

I posted this teaser the other day, but I’ll post it again

River sat across from Jack, sipping a glass of wine and watching the rest of the bar. The crowd was mostly human, but a few other species dotted the room. Her smile brightened as a blonde man walked in. Jack raised an eyebrow and turned to see what had grabbed her attention and went pale. “Oh God.”

The blonde man gave a feral grin as he flounced over and slipped into an empty seat between them. “Jack!”

“John,” he said with a wince.  

“So you know each other,” grinned River. 

“Oh we do, but he never mentioned you.” John picked up her hand with a dramatic flourish to kiss it.

River watched him with a knowing smile as he kissed every inch of her fingers and then let them fall. “I’ll take the ring back, thank you.” She held out her hand expectantly, palm up. 

Grinning, John took the ring out of his mouth and placed it in her open hand.

Looking at the pair, Jack raised his hand for the waiter. He lifted his half-empty glass. “Get me a double.”

John leaned over. “If you wanted a double, Jack…”

River laughed. “Oh Jack I like him.”

Jack threw back the rest of his drink. “You can have him,” he spat.

Undeterred, John leaned over and put a hand on Jack’s thigh. “Come now, more than enough to share,” he said with a suggestive wag of his eyebrows.

Jack pulled away. “You’re wearing the lip gloss.”

“Come on, not like you’d stay dead very long,” John purred.

River raised an eyebrow. “He does know you. What brand do you use?”

John turned back to her, intrigued. “Paranthian. What do you use?”

“I find Halver’s does a better job.”

“Really? I don’t think that moisturizes as well…”

Jack took their animated discussion over types and brands of paralytic lips gloss as a chance to escape to the bar and see about that drink.