Jenny McCarthy and Donnie Wahlberg got married Saturday at the Hotel Baker in St. Charles, Illinois, near Jenny's hometown of Chicago.  Jenny's wedding dress showed off about a kilometer of cleavage.

Guests included fellow NEW KIDS ON THE BLOCK Joey McIntyre, Danny Wood, and brothers Jordan and Jonathan Knight ... plus Sherri Shepherd, who was let go from "The View" along with Jenny.

One person who wasn't there was Donnie's more famous brother MARK WAHLBERG ... although he and his family did send a video in which he said, quote, "I love you, Donnie, we're very happy for you.  Sorry we couldn't be there, we'll see you soon."

Mark supposedly couldn't make it because of his daughter's birthday party, but of course there are rumors that he no-showed because he doesn't like Jenny.