Camila Cabello and Shawn Mendes looked "flirty and very close" during a recent date in San Francisco

The onlooker told E! News: "They definitely looked like a couple."

The former Fifth Harmony star and Shawn reportedly shared a spread of pancakes, omelettes and bacon as they ate together at a local cafe.

According to the eyewitness, Shawn - who previously collaborated with Camila on the single 'I Know What You Did Last Summer' - paid the bill for them both.

In recent weeks, Camila has denied she is dating Shawn - although she admitted they have a "rare" relationship.

She shared: "I've never had a lot of friends. I've always just had a few people in my life that I trust.

"I feel like it's so rare to meet someone in this industry and find a person of that quality, and I feel like Shawn is that person for me.

"I just trust him, and no matter the level of intensity that he has around his career or I have, he is just normal, and that is so rare and precious to find in this industry. To be able to hang out with someone and you don't really care that they're Shawn Mendes, you know what I mean?

"You're just people, and that is definitely something that is rare ... It's actually a really beautiful feeling to know that this person is always going to be in my life, we're always going to love each other."