She finds out

Keith and Shiro have a plan to confess their feelings to Lance, but after Keith hears Lance talking to himself. Plans change.

Allura walk by Lances opened door and sees "her" Shiro with Keith and Lance. The only feeling she has is anger, towards Lance and Keith, and love towards Shiro.

Allura makes a vow to herself that she will get her way and will get "her" Shiro back and will hurt maybe kill Lance and Keith.