YouTube star Zeinab Harake celebrated the birthday of her adopted son, Lucas, who turned five years old on Monday, July 18.

On Instagram, Zeinab penned a touching message for her son as she posted their photo together.

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"Happy birthday kuya Lucas I love you so so much higit sa buhay ko," she wrote.

"Thank you for making my 5yrs happy so blessed to have u anak ikaw ang #1 boy sa heart ni mommy."

Zeinab, now 23, adopted her son Lucas when she was only 18 years old.

Explaining on Toni Talks why she decided to adopt a child at such a young age, the vlogger said: "Kasi nga gusto ko magka-baby. Oo.

"Nung nakita ko kasi 'yung bata, andoon 'yung puso ko na, 'Aww. Gusto ko 'to. Gusto ko 'to."

READ: Zeinab Harake sa pagbubuntis niya: ‘Hindi ‘to karma’

Zeinab has since given birth to her biological daughter, Bia, with her former partner, rapper Skusta Clee.

The pair also had a son, Moon Harake, whom they lost to a miscarriage earlier this year.