Reese Witherspoon got married on Saturday, but the poor dear’s Will the Circle Be Broken was outshined by the first public appearance of Scarlett Johansson and Sean Penn as a couple. It turns out that Scarlett is a client of Reese’s now-husband, and Rob Shuter reported that everyone was shocked to see she brought Sean Penn as her plus one. Apparently, their outing was a huge deal, as a source told Rob that their arrival together “is announcing to the whole of Hollywood that they are serious.” Previously, Scarlett and Sean were seen celebrating…