To cross twice in hybridization, as (A × B) × (C × D); for example, in commercial hybrid seed corn, A through D are classically inbreds, and their grandoffspring is the seed for sale.
pull the wool over someone's eyes
verb
To deceive someone.
How often have the words double-cross and pull the wool over someone's eyes occurred in a corpus of books? (source: Google Ngram Viewer )