Dear Ami,
Can so identify with the type of 'sabotage' you refer to.
My now exH would not communicate with a colleague from work who had dropped in for a coffee -- just same in his armchair, saying zilch ---- the atmosphere was tense, with me trying to make up for the void he created. Ignorance, pure and simply, but, with a purpose and a plan. Next day, at work, all eyes of Leah, and my colleague kept her distance from that day on.
He did not like my having friends at work, oh, he loved for me to go out to work, yes, but not to enjoy it.
My mother, upon reflection, created problems with my friends, and they too would not like to call, all with the exception of one, who my mother ensnared in her Nwebment!! Because this friend was the daughter of her friend, and it is a very long painful story.
Sabotage for the purpose of control and manipulation --- and isolation.
Love, Leah