Clearly he was already outnumbered, which he wasn't surprised by. If James and Sirius were on board with something, it didn't take much for Peter to follow along and of course they were on the same page now. Remus listened, pouring the drinks and passing them around as he chewed the idea over.
Then he took a swig and began literally chewing on his thumb nail, both a good and bad sign.
"I'm not saying we don't have to find the Order, but I don't think this is actually a good idea." He hated shooting down their plans, but he couldn't keep thoughts like this to himself. Not all the time. "What if it actually goes badly? If someone gets hurt. If the Order doesn't even come. Or if they just say it's our fault and reprimand us while never letting us join."
He let that sink in, looking from one face to another, studying his friends' reactions. At least James had made sense; of course they would have to confirm actual Death Eaters before doing anything too rash, or they'd risk even more. Still, he wasn't so certain about this 'plan' and his mind was working to come up with something that would actually work, thus the chewing-on-his-nail.