What Bet? Your Proclaimed Bet? Not Interested

It seemed my reply startled him, as he paused for a moment before saying:

"Let's stop joking, I need to speak seriously with you."

"About your proclaimed fair bet? Sorry, not interested."

"C'mon, haven't we agreed not to joke anymore? I know you are interested."

"Who said I agreed on no joking?" I said while sticking out my tongue to him, "You just need to think of a fair bet and I would really consider it."

I heard a sneer from him followed by a chuckle, so I didn't know if he was discontent or happy with my reply. I kept attacking and pushing the way forward while he replied after couple of minutes:

"How about that, it's the same previous conditions, however the judge wouldn't be me, Aria will be the judge. What do you think?"

"Unacceptable, Aria is a closer friend to you than me."

I frankly heard the sound of gritting his teeth while replying:

"What do you propose then?"

"Hmm, let one of my group judge then."