Alice de Stuteville - Incestuous Loop?

I'm probably becoming the Curators' and Managers' worst nightmare at this point, but I'm working back and forth between here and Ancestry using (mostly) the pedigree view at Ancestry and Alice de Stuteville appears to have married her nephew, since she and Emma de Stuteville are half-siblings and Guillaume de Grandmesnil, Heir of the honour of Grandmesnil, is the son of Emma de Stuteville. Bad merges?

Daughter of Robert le Grandbois d'Estouteville, Lord of Cottingham and Aélis de Beaumont-sur-Oise
Wife of Sir Michael le Fleming, Knight, of Aldingham and Guillaume de Grandmesnil, Heir of the honour of Grandmesnil