Mummy Tee Rak follows the intertwined lives of three families.

Primma becomes pregnant by her boyfriend, Panu, just as he's about to study abroad. To protect his future, she hides the pregnancy and chooses to raise the child alone. Years later, Panu returns and discovers the truth, determined to win her back—only to find she now has another suitor, Peera, a kind-hearted chef.

Gunnaree, a career-driven financial controller, wants a child and decides to freeze her eggs. She meets Chanachol, who agrees to donate sperm as he also dreams of becoming a father. However, the law blocks insemination for unmarried couples. Gunnaree proposes a temporary marriage, and Chanachol agrees—though he secretly still loves someone else.

Meanwhile, Sarinta struggles in a loveless marriage with Poramet, a rigid politician obsessed with public image above all else.