A Moreno Valley man who fatally shot his ex-girlfriend’s new lover — in front of their children — in a state of extreme jealousy was bound for state prison Monday to serve 50 years to life behind bars. Jerome Roy Jackson, 37, killed Jason Williams, 38, of Riverside in 2022. In April, a Riverside jury convicted Jackson of first-degree murder, two counts of child endangerment and sentence-enhancing gun and great bodily injury allegations. During a…