A liquid container lid assembly includes a straw having an internal one-way valve and a grommet seal for sealing against the straw. As a result, the disclosed liquid container lid assembly allows a consumer (such as a child) to drink from the straw while preventing accidental spillage without the need for the child to manipulate any part of the lid assembly (such as a lock or valve release). In other words, the liquid container lid assembly is always in a no-spill configuration while simultaneously allowing a consumer to drink from the straw.