they're definitely not the best of buddies anymore. Tony and Silvio both know Paulie was telling Johnny Sack about all his problems with Tony. Silvio seems kinda paranoid too about gradually losing the number 2 spot to christopher and he knows paulie would love to be the number 2 also. If you really wanna see the start of everything watch episode 12 in season four silvio and paulie get in each other's faces at the bada bing.