The 30-year-old singer has revealed how the 'Game of Thrones' star is such a huge fan of the wizard movies - which were adapted for the big screen from J.K. Rowling's book saga - and she wanted her man to have experienced the franchise.
Appearing on 'The Late Late Show with James Corden', he revealed: ''Sophie, she said, 'Look, if we're going to get married' and it was actually, 'If you're going to date me, you have to watch the Harry 'Potters''.
''Because every Christmas, for those of you that are watching that don't know, every Christmas in the UK they just stream and play 'Harry Potter', all of them.''
The 'Sucker' hitmaker admitted he ''fell in love'' with the film series, and in return he insisted his wife returned the favour by catching up on 'Lord of the Rings' during lockdown.
And to complement their viewing, Joe explained how the married couple - who tied the knot last year and were reported in February to be expecting their first child together - have been working on ''plenty'' of Lego toy sets.
He added: ''We've done three Lord of the Rings Legos, we've done Hogwarts, the castle, which is like 7,000 pieces, the Batmobile, and 'Stranger Things'. So we're running out of options at this point.''
His comments come after it was revealed Joe and Sophie, 24, had sent 100 meals to healthcare workers in Los Angeles amid the coronavirus pandemic.
The couple sent the meals to East Los Angeles Doctors Hospital as part of the Fuelling the Fearless campaign, which works to hire local restaurants struggling to make ends meet as a result of the crisis.
The news was confirmed by Fuelling the Fearless on their Instagram account, where they thanked the couple for their contributions, as well as the Jonas Brothers' manager Phil McIntyre and wife Shonda McIntyre.
They wrote: ''A BIG THANK YOU to @joejonas @sophiet @philymack @shondamcintyre for donating 100 meals to East LA Doctors Hospital.
''This hospital is in the heart of downtown LA and serves a vastly underprivileged community with limited resources and support. The staff work tirelessly to care for the community and those often forgotten.
''Through these type of fully paid sponsorships @alikisgreektaverna and her donors bring a moment of relief to a most grateful staff. One hot meal lets them know we are all in this together. (sic)''
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