"Jen knew about the new relationship and still chose to go on vacation with Ben for the 4th of July," a source told Us Weekly. "She is OK with it."
Ben and Jen, who split in June 2015 but only filed for divorce this year, took their three children — Violet, 11, Seraphina, 8, and Samuel, 5 — on a Caribbean vacation before the holiday. They also attended a parade together on Independence Day.
One source told Us that the romance has been going on for years.
"Ben and Lindsay started their affair in 2015. They were not casually dating — they were having a full-blown affair," a source close told the mag. "They were sleeping together, sending each other cute texts and meeting up whenever they could." That same source said Jen was "devastated" when she first learned of the relationship.
But, another source said, Ben and Lindsay have been "casually dating for three months."
A source also told X17 that Ben and Lindsay, who recently spent time in London together, are hardly in the initial stages, saying that Lindsay and Ben dated before he got together with Jennifer.
The site quotes a source as saying "Ben made frequent trips to New York over the years to see Lindsay" and that "they always had a strong connection."