and are adding to the summer heat wave!
The costars were seen sharing a steamy smooch inside a car Thursday in photos obtained by .
Other photos taken showed the pair out and about together, with Zendaya, 24, in a halter-style white crop top and green bottoms, accessorizing with a pair of hoop earrings.
Meanwhile, Holland, 25, kept it casual in a white T-shirt and blue flannel overshirt, over a pair of drawstring pants.
Zendaya's mother, Claire Stoermer, was also seen spending time with the pair that day.
Reps for both actors did not immediately respond to PEOPLE's requests for comment.
A source previously told PEOPLE back in July 2017 that .
"They started seeing each other while they were filming ," said the insider. "They've been super careful to keep it private and out of the public eye but they've gone on vacations with each other and try and spend as much time as possible with one another."
Added another source, "They're both really ambitious and they challenge each other — but, most importantly, . They seem to have a really similar sense of humor and love joking around together. They have great banter back and forth."
Zendaya seemingly that same month, tweeting, "My favorite is when it says we go on vacations together HA! I haven't been on a vacation in years!😂😭🤣hbu
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In August of that year, the actress told she and Holland were not together romantically, adding, "He's literally one of my best friends. This past how many months we've had to do press tours together. There's very few people that will understand what that's like at 20 years old."
RELATED VIDEO: Zendaya and Costar Tom Holland Are Dating
In a recent cover story for , Holland said talking to Zendaya about fame "helped [him] a lot," in the sense that he "used to come across sometimes as a bit of a d--- to fans" unintentionally. According to the actor, Zendaya "totally changed the way I am able to be more comfortable in public.
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Listen below to for more on Zendaya and Tom Holland.
He also touched on — particularly how it can be "frustrating" to have relationships play out in the spotlight.
"It's very nerve-racking. It means that if you dating someone, you have to be really conscious of their feelings, because if something does happen between the two of you, it's not just happening between the two of you, it's happening in front of the entire world," he said. "It's one of the things I worry about most, of all the things in my career."
This is not the first (or even second!) time a franchise has yielded real-life romance.
and began dating while shooting 2002's , but ended their relationship before shooting 2007's .
and began dating after filming 2012's . The two confirmed they'd split in 2015, but .
Zendaya and Holland's third movie together, , opens Dec. 17.
