The lovely garment also accentuated her growing baby bump.
Arie complimented her in neutral tones as well.
A boy AND a girl: Bachelor Nation's Arie Luyendyk Jr and his wife Lauren Burnham-Luyendyk have revealed the sex of their rainbow twins due in July
Ever the prepared parents, Arie and Lauren even have an Instagram page set up for the twins already, with a sonogram picture serving as their profile pic.
On December 19, the pair first announced that they were expecting their second child.
And two days later, they took to their YouTube channel to share the happy development that Lauren is expecting twins.