Marvin Agustin writes heartfelt message for his twin sons on their 15th birthday

Marvin Agustin took to Instagram to greet his twin sons, Sebastian and Santiago, on their 15th birthday.

Posting a photo from when the twins were babies and another that showed their present selves, Marvin thanked the boys for giving him the opportunity to be their father.

He began, "15 years ago dumating kayo sa buhay namin. 15 years na din akong kabado kung tama at maayos ba ang trabaho ko bilang tatay. Pero hindi nyo yun dapat intindihin, yan ang responsibilidad na pinasok ko."

While Marvin said he doesn't "know whats best for you boys, kasi ang buhay niyo ay laban niyo," the actor and entrepreneur assured his sons that he's always there for them.

"Mas gusto kong makilala niyo sarili niyo at walang ibang magsabi sa inyo kung ano at dapat niyong piliin sa kaligayahan niyo at maaring kaligayahan na maibibigay niyo sa iba," he added.

Thanking them for giving him the experience and opportunity to be their dad, Marvin said, "Mahirap ang pinagdadaanan natin ngayon pero masaya ako sa maliliit na bagay na napagtatawanan at ikinaliligaya pa din natin." 

Marvin ended his note with a birthday greeting and a joke.

"Happy birthday handsomes! Kung hindi nyo maintindihan ang mga sinabi ko, ask your mom. She will translate in English," Marvin wrote.

On Father's Day last June, Marvin shared a photo of him with his boys from when they were small, and said it was his "favorite photo and job."

"You guys challenge me to be the best, not just a dad but the best person I can be," he added.

Sebastian and Santiago are Marvin's sons to Tetet Dy, from whom he is already separated. — Jannielyn Ann Bigtas/LA, GMA News