According to reports, Neymar and Bruna were dating until they split in January, with the popular soccer star moving on with model Gabriella Lenzi.
But after Brazil's winning match against Croatia on June 12, Neymar reignited rumours the pair are back together after posting a picture of him and Bruna to his Instagram page.
In Portuguese, he captioned the snap: 'Thanks for being part of this moment, this great dream I'm doing! Today was an almost perfect day ... Just missed seeing you kkkk Happy Valentine's Day my love! Love you.'
Bruna is a Brazilian actress who stars in Em Familia, a soap opera which launched in February 2014. She's just 18 years old, but has already starred in several different TV shows and short films.
The teenager was born in Rio, and her Twitter profile encourages her 1.6 million followers to 'Always laugh when you can. It is cheap medicine.'
She too shared a photo of her and Neymar together, writing:
'Love ... Today is a very special day for you, the day u get to live one of their biggest dreams and I'm very happy that I get to watch you! How much will always be cheering for you! May God protect you above all, bless and guide you at every turn! I know it will be much better than you dreamed! Step onto the pitch today and give your show, I will be proudly watching u doing what you love! Sorteeee good! Eeeeeeee ... It's a very special day for us! Another Valentine's Day together and I love every passing over your day smell, his kiss, love even his faults! Everything! I tell you how much I love you everyday ... But I'll say it again! Love you, you make me very happy and I wish much love and much happiness for us!'
Meanwhile some news sites are reporting that Neymar could still be seeing Gabriella Lenzi, who has also been tweeting and Instagramming her support of Brazil during the World Cup.