The song is "The Spicy McHaggis Jig" by the Dropkick Murphys, which I HIGHLY recommend listening to.
The Wardens, the Spymaster, the Altus and the Storyteller crowded around one table in the Herald's Rest. Ale was flowing and everyone was having a great time. Lixa noticed that they were being given a bit of a wider berth, but that was mainly on account of how loud they were being. People still seemed a little unsure how to act around the living legends, despite the fact that they'd been part of the Inquisition since its formation. It didn't help that Lixa, Theron, and Oghren seemed to be humming. As the humming continued, Derek and Zevran started keeping a beat on the table, using their tankards as much as their hands. Lixa started whistling, and apparently this was the cue for the others to start singing:
We'll tell you a story, believe me it's true
A tale you'd best hope, never happens to you
Old Spicy McNuggins, how he met his fate
You I can save, but for him it's too late!
Everyone in the tavern was watching as Lixa and Zevran climbed onto the table and started dancing. They danced amongst the tankards and bottles which Derek, Theron, and Oghren used to continue the beat, all belting out the song.
Spicy was big, burly and strong
His pipes were gigantic, and so was his schlong!
From city to city, running around
Always looking for girls over four hundred pounds!
Dorian choked on his wine while Varric looked on with a rather amused expression (which was in part because of Leliana quietly singing along). Sera came down from her room and was standing by the stairs, clearly unsure of what was going on.
One night at the pub, a girl caught his eye
Big as a house, just the right size
The broad was enormous, stacked to the hilt
Spicy soon noticed a bulge in his kilt
Berserker delivered his best pick-up line
Thought to himself, "This beast is all mine"
The portly young lady could stand for no more
Grabbed his cojones and ran for the door
Blackwall and Cullen were guffawing into their drinks, slumped over on their table. Josephine watched the spectacle bemusedly, a look of both wanting to join in and concern on her face.
They got to her house and put out the lights
Spicy was in for one hell of a night
He said that he loved her, he'd always be true
"But Mr. McNuggins, I've only just met you!"
The previous line was sung by only Lixa, in a ridiculous high-pitched voice and accompanied by much batting of her eyelashes. The Chargers were swaying along to the song, helping hold the beat by banging their drinks together. Bull was doubled over with laughter, with Sera perched on his shoulders howling and clinging to his horns in order to not fall.
By now he saw double through his drunken eyes
Neither had looks or appropriate size
He came to his senses, thought to himself
"At this time of night I won't find anything else"
He took off his shirt, she lifted her skirt
They pulled out his unit and started to play
She asked for a glove, he gave her a shove
Had baby McNuggins nine months to-the-day
Cabot smirked at the usually relatively composed group of patrons, while simultaneously threatening "teetotalism for anyone who wrecked his bar".
SPICY! SPICY! SPICY! SPICY! SPICY! SPICY! SPICY! SPICY!
The Chargers joined in with the chanting, and so did Sutherland and company from the second floor.
One night at the pub, a girl caught his eye
Big as a house, just the right size
The broad was enormous, stacked to the hilt
Spicy soon noticed a bulge in his kilt
Berserker delivered his best pick-up line
Thought to himself, "This beast is all mine"
The portly young lady could stand for no more
Grabbed his cojones and ran for the door
Lixa and Zevran stopped dancing, instead sitting on the table, swaying back and forth together.
Three kegs a day, he'll drink 'til he dies
Spicy McNuggins, one hell of a guy!
At the conclusion of the song, everyone let out a cheer and drained their drinks. Lixa and Zevran returned to their seats, and all of the Wardens acted as if nothing unusual just happened, despite everyone in the tavern staring.
"So…what was that?" Dorian asked from his seat between Theron and Derek. Bull came over to their table (Sera still draped across his shoulders, unable to stop laughing), and the Chargers all leaned forward, clearly eager to find out.
Zevran laughed and raised his drink. "A song!"
"We came up with it one day when we were all REALLY drunk. It's about Oghren." Lixa stated calmly, as if discussing the weather.
"But don't tell my wife!" Oghren yelled frantically, quickly checking to make sure Felsi wasn't around.
"Some things never change, I see," Cullen called over, which caused a horrified expression to appear on the Ambassador's face.
"You-you mean I should expect more such behaviour?" Josephine stammered, clearly thinking of the potential diplomatic pitfalls this presented.
"Well, it is one of King Alistair's favourite songs. After all, he did help write it," Leliana stated, enjoying the look of tormented anguish her friend was sporting. Josephine appeared positively faint, and promptly asked for another drink. Blackwall, who had managed to stop laughing, quickly erupted again.
"…Can you teach us?" Bull, Krem, and Stitches all asked, with the rest of the Chargers trying – and failing – to act as if they didn't care.
Lixa glanced around at the rest of the Wardens, before grinning maniacally. "Why not!"
Varric chuckled to himself, "Feels like home."