But they're not just laughing at the fact they're set to make fortunes, thanks to the announcement Still Game will be returning as a stage show at the new venue next year over four nights.
Nor are the smiles on their faces a result of the fact they've announced the adventures of Jack and Victor will continue on BBC Scotland, either in a Christmas or New Year special for 2014, or a whole new series.
The delight on their faces seems to be emerging from the pleasure they're having in not only working together - but being pals again.
"It's going to great to be back together at the typewriter," said Greg. "Typewriter?" said Ford.
"We've moved on, daftie. We've got keyboards now."
The fact the pair are abusing each other, in the nicest possible sense, confirms the chemistry which once made them Scotland's most successful writing/acting duo is still in existence.
The creators of the sitcom, which ran for five years on BBC Scotland until the stars parted company after disputes about which direction to take the partnership, have clearly put the past behind them.
And today the pair revealed they are "massively excited" about the return to the fictitious world of Craiglang.
But does it all feel a little strange? Like a couple who've split and gotten back together.
"These past few days have been really good," said Ford.
"It's like meeting your cousin or a long lost brother after a few years. But once you get the awkwardness out of the way it's great."
Greg agreed, he said: "I've been in Los Angeles with the family, putting a toe in the water, and I'll be going back there for a few months.
"But I'm looking forward to coming back in the New Year and getting down to writing with Ford. It'll be like old times."
The pair are going to spend inbetween time revisiting the show, trying to work out how to take it forward.
"For the stage show, I like the idea of doing moments from the sitcom which people loved, while weaving a new story into the mix as well," says Greg.
"It's a bit like when a great band appears. You want to hear the greatest hits."
Ford said: "We'll give the audience a wee flavour of what made Still Game successful, but then 90% of the show will be new."
n Still Game - Live At The Hydro, September 30 - October 3, next year. Tickets, priced £45 and £30, go on sale on tomorrow.