The teenager was answering fan questions from his 1.8 million Instagram followers, when someone posed the query.
Although Cruz was more than happy to respond to the fan question, he did make a small attempt to hide the answer away as he wrote it in small text.
WATCH: David Beckham gets told off as he interrupts son Cruz's singing
Alongside a picture of himself in a mask, the teen revealed that his crush was none other than Bad Guy singer Billie Eilish.
Billie shot to fame at the age of 14 after she uploaded her song Ocean Eyes to SoundCloud. The singer's debut album in 2019 was released to international success and was one of the highest-selling albums of the year.
Her career has continued to go from success to success as she became the youngest ever person to win a Grammy Award and recorded the title theme for the upcoming James Bond film, No Time to Die.
In other fan questions, Cruz revealed that his favourite colours are orange and purple and that he was working on some new music for fans.
The teen was answering questions on Instagram
He has previously wowed fans with a cover version of Charlie Puth's 2015 hit One Call Away and released his own Christmas song back in 2016, If Everyday Was Christmas.
The young singer turned 16 back in February, and alongside a killer birthday cake, he also celebrated by unveiling an edgy new piercing – much like his famous dad used to sport.
After sharing a selfie captioned, "It's ma burfday," on his Instagram Stories, Cruz went on to post a close-up picture of his earlobe with what appears to be a mini grey skull earring.
Cruz revealed that Billie Eilish was his celebrity crush
Getting piercings runs in the Beckham family, as alongside David and Victoria, both of Cruz's older brothers have had piercings done in the past; Brooklyn being accompanied by his parents during a trip to Claire's in 2014, and three years later, Romeo, then 14, modelled earrings in a snap with his cousin.
The Beckham clan paid tribute to Cruz on social media on his birthday, with VB sharing a video of him singing and gushing: "Happy Birthday!! @cruzbeckham we all love u so much xxxx We are so proud of the man you have turned into! So sweet and so kind x we love you x kisses @davidbeckham @brooklynbeckham @romeobeckham #harperseven x."
David similarly marked his son's special day with a series of photos and videos of Cruz growing up. The doting dad added: "Happy 16th Birthday to my little man... Have the most amazing day, dad is so proud of you, love you always and forever. Sorry about the singing @cruzbeckham @victoriabeckham @brooklynbeckham @romeobeckham #HarperSeven @friends."
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