British Undercover Officers in Trouble for Seducing Activists: Good lord, this is insane. Using the names of dead infants for their cover identities, having years-long live-in relationships with people they were spying on—even fathering children. The Guardian has a long piece on one such relationship:
By the spring of 1995, Jenner began a relationship with Alison and soon moved into her flat. "We lived together as what I would describe as man and wife," she said. "He was completely integrated into my life for five years." Jenner met her relatives, who trusted him as her long-term partner. He accompanied Alison to her mother's second wedding. "He is in my mother's wedding photograph," she said.