Dean didn't like it. Sam knew that he wouldn't. Fortunately, Dad seemed to find it a sound tactic. Five minutes was all he needed to distract Azazel. Dad and Dean only needed but a few seconds to untie and/or unlock whatever was holding Mom, so Sam wasn't worried about that. He'd give them time to escape, then Sam would work at doing the same. If Dean showed up to back him, then fine. Sam didn't like the idea of Dean being the one in harms way, but he'd deal with it. He'd make sure they both got out, because if he didn't...Sam turned, watching as Dean took the lead and started for the building. He wouldn't lose him. Dean would make it out, Mom would make it out, Dad would make it out - they'd all make it out. Sam might have been making the stupid, sacrificial move here, but he'd be damned if he let Azazel have his way with him or anyone else in his family. They were all getting out. Sam was very set on that much, at least.
Shouldering his axe, Sam shot Dad a smug look at Dean's retreating figure. A tiny smirk was quick to follow before Sam turned and followed his brother. Dean rebelling against Dad's orders, ignoring everything that the man had to say, and taking off on his own without a single word. Sam had to admit, that kind of made him feel all warm and tingly inside.
Keeping an eye on their surroundings, Sam chose to move quickly. Azazel had hidden all entrances and exits to the building Mom was trapped in, which meant that the sound of their hacking at the walls was going to alert him pretty damn quick of their presence if he was nearby. They'd have to be quick and precise if they wanted to get this done, otherwise Sam was going to have to play decoy for much longer than even he wanted to.