Mom's lap is "the spot to be" in my house, too. When any one of them is on my lap while I am on the computer (like Mac is right now) one of the others will sometime come close and glare and grow. Ming is the only one who isn't enthralled with lap sitting, but he does get jealous if Mac or Kimba is up there. Typical cat behavior.
We are keeping paws and fingers crossed that Pouncer will soon be good as gold!