The actress, who plays Lily Bloom in the film, has so far wowed in a selection of knock-out floral dresses inspired by her character on the film's promo trail.
The pair appeared tense, jubilant and nervous - at times hiding their faces behind their hands - as they watched the men's 3x3 basketball at La Concorde in Paris on Monday.
The former glamour model was absent at a scheduled £760,000 bankruptcy court hearing on Tuesday, having flown overseas for her latest cosmetic procedure.
The French president, who is beleaguered by political chaos after calling a last minute election earlier this summer, told participants afterwards to be 'proud' of their performance.
Humphries is a very short odds-on favourite at 4/9 to come away with the victory, while Van Gerwen is a 13/8 outsider, according to Sky Bet.
The 21-year-old is likely to leave City this summer, either on loan or on a permanent basis, as he is not yet viewed as ready for regular first-team football at the Etihad Stadium.
