Nima Momeni and Bob Lee
Nima Momeni, left, faces a murder charge in connection to the fatal stabbing of Cash App founder Bob Lee, right.
  • Nima Momeni is facing a murder charge in connection to the death of Cash App founder Bob Lee.
  • Lee dated Momeni's ex-girlfriend about three years ago, sources told The Wall Street Journal.
  • At a later point, Lee began casually sleeping with Momeni's sister, Khazar, per WSJ.

Cash App founder Bob Lee dated his murder suspect's ex-girlfriend before he began casually sleeping with the alleged killer's sister, Khazar Momeni, friends familiar with Lee's relationships told The Wall Street Journal.