尽情 (jìn qíng): มากที่สุดเท่าที่ชอบ

At the graduation party, the classmates sang and danced to their hearts' content, not leaving reluctantly until midnight.

On a rainy day, the children happily stomped in puddles on the playground, not caring that their clothes were soaked through.

After retiring, he could finally read and travel to his heart's content, enjoying a free and easy life.