The Twilight star and his wife, Sheila Hafsadi, announced they are expanding their family in March (16), and on Monday (30May16), Jackson shared a photo of the pregnant mother-to-be lounging in her bikini on America's Memorial Day holiday.

He captioned the black and white Instagram snap, "The wifey at #39weeks and one day! Soon, baby, soon..."

The couple is scheduled to give son Monroe, who turns four in July (16), a sibling any day now.

Jackson and burlesque dancer Sheila wed in 2013.