There's no amount of No big enough for what this situation devolved into.
This has all been pushed too far, too fast, and there's not a damn thing Mike can do about it.

Not that this will keep him from trying.
To stand by idle will likely result the death of both of his cousins; one from being beaten, and the other for doing the beating.

"Raph no!" he bellows as he tries to insert himself between them both before the blow is landed.