Before scandal rocked their marriage, Cheryl Hines and Robert F. Kennedy Jr. were a loved-up duo. The power couple’s union was altered when it was alleged that the politician, 70, had an inappropriate texting relationship with journalist Olivia Nuzzi, 31, after the reporter highlighted him for a feature. Now, Kennedy Jr.’s romance with the Curb Your Enthusiasm actress, 59 — whom he wed in 2014 — hangs in balance. “She’s been talking about filing for divorce, but he’s begging her not to file,” an insider claimed. “But how many times can you forgive a partner that’s dishonest and goes behind you…