West, 50, and FitzGerald, 49, put on a united front on Tuesday as they were photographed together outside of their home in London.
The married couple locked lips for cameras outside of their residence and even shared a public statement that was handwritten on a piece of paper that read, "Our marriage is strong and we're very much still together. Thank you. Catherine and Dominic."
Meanwhile, just one day prior, the Daily Mail published photos of West and James, 31, sightseeing around Rome, Italy on a scooter and enjoying lunch. One photo that raised eyebrows and fueled cheating rumors appeared to show West leaning into James' cheek.
West and FitzGerald married in 2010 and share four kids together. "The Affair" star also has an older child from a previous relationship. James, on the other hand, has been previously linked to Chris Evans and dated Matt Smith for five years.
West and James are currently filming a new BBC series, "The Pursuit of Love," based on Nancy Mitford's novel in the U.K. Amazon is set to stream it in the U.S.
"They worked together in the past but seem to have connected in a special way since they started filming in England over the summer," a source told People magazine.
Reps for West and James didn't immediately return Fox News' request for comment.