Mark Hamill was 'blissfully unaware' of 'Star Wars' affair between Carrie Fisher and Harrison Ford

Guess he couldn't feel it in The Force.

Mark Hamill told Entertainment Tonight in a recent interview that he had no clue his Star Wars co-stars Harrison Ford and Carrie Fisher were having an affair while the trio was shooting A New Hope in England back in 1976.

Fisher broke the news of the real-life Han and Leia romance in her new book, The Princess Diarist, in which she said the pair had multiple "sleepovers" despite the fact that Ford was married at the time.

The rendezvous between the two stayed secret for almost 40 years and clearly they kept a lid on it during production, too, the 65-year-old Hamill told ET, adding he was "blissfully unaware."

See photos of Carrie Fisher and Harrison Ford:

"I was so self-involved at that point, they could've been doing it in front of me and I wouldn't have noticed," Hamill said. "I was single and had my own agenda."

The actor, who is bringing Luke Skywalker back to life yet again for the next Star Wars installment, the still untitled Episode VIII, said it was good people didn't know about the fling at the time, as it may have gotten in the way of production.

"If the relationship doesn't last and you're on a TV series and you got four more seasons to go, it can be really awkward," Hamill said. "It happened to me. I was with a girl [Anne Wyndham] who was playing my sister on a soap opera, General Hospital."

Fisher wrote in her book, which included pages of the journal she kept back in 1976, that she fell hard for Ford even though she was 19 and he was 33 and married. In the end, the affair ended after the movie wrapped. Fisher also noted in her book that a part of her still longs to be with Ford, who is now married to Calista Flockhart. She of course said it wasn't going to happen, though. Fisher also said Ford was likely not pleased she brought their personal life, albeit from a long time ago, to light.

Read more: Carrie Fisher Says She "Ambushed" Harrison Ford With Affair Admission in Book