The 38-year-old who is nearing 10 million followers wrote on the Instagram caption in Spanish and English: "Felices 5 meses Sasha! / Happy 5 months Sasha!"
The gorgeous boy shows four different facial expressions - with one huge smile that made our hearts melt a
Although Sasha doesn't look best pleased about his mini-photoshoot, the photo prompted more than 8,000 comments of hearts and a lot of "cute" and "gorgeous" comments.
And check out those peepers!
The singer gave birth on 29 January to Sasha, her second child with partner and Spanish football player, Gerard Piqué.
Their first son Milan was born in January 2013 in Barcelona. Piqué uploaded a photo of him and his two boys in May 2015.
Unlike Sasha's bright blue eyes and fair hair, Milan has brown eyes like his mother.
Els meus dos mites. pic.twitter.com/IweqNLQlXM— Gerard Piqué (@3gerardpique) May 18, 2015