WI: no Portugal, bigger León instead

[GauchoBadger]

Suppose that Afonso I of Portugal loses the Battle of São Marmede (1128 AD) and, thus, never forms Portugal as an independent country.
How could this affect the makeup of the iberian christian kingdoms? Would Castile and León remain separate?

 

[Sevarics]

The high amounts of intermarriage could still lead to a union of Castile and Leon. But the country could always split again?