The invention provides a lid assembly (1) comprising a lid housing (10) with a circumferential side wall and a drinking opening (12), a sealing assembly (20) with sealing element (21) moveable between a first and second position for closing and opening the drinking opening (12), and an operating assembly (40) to move the sealing element (21) between first and second position. The invention further concerns an interior mechanism for a lid assembly, and a drinking container comprising such a lid assembly.