If there was one thing Sirius was not worried about, it was losing his friend. He was confident to the point of cocky, and that thought simply never crossed his mind. Sirius couldn't survive without James, and so he thought the same was true for James - he wouldn't be able to survive without Sirius. As for Remus, Sirius was quite certain he wouldn't trade any of them in. Who else would accept the fact he was a werewolf with such positive enthusiasm? Besides, Sirius was amazing, why wouldn't they want to be his best mate? He had a mind for adventure, and without him, Sirius reckoned these three would have pretty boring lives.
Sirius simply rose an eyebrow in response to James' words. "What in the bloody hell are you talking about? Merlin Prongs, if you and Moony know about it, then yeah, I want to know. I also want to know why you chose to wait so long for this creepy meeting, and why it seems the whole house of Gryffindor knows before I -- we did." Sirius said, his words getting angrier by the second. He wasn't exactly impressed with the fact James was talking like a madman, Remus was sitting there not saying a word, and Peter was practically drained of colour.
"Stop stalling. Evans already told me of a 'gathering', so I'm assuming that's where you all were. Without me." Sirius said, and quickly added "without Peter."