New dad Prince William kisses future sister-in-law Meghan Markle at Westminster Abbey: See the sweet photos

The soon-to-be in-laws are getting along swimmingly!

Two days after welcoming his third child with wife Kate, Prince William joined Prince Harry and Meghan Markle for an Anzac Day Service at Westminster Abbey. Upon his arrival, Wills greeted his future sister-in-law with a warm hug and kiss.

Although some of the royals have been seen exchanging cheek kisses, the family is notoriously cautious about public displays of affection, so the moment came as a sweet surprise.

According to reports, Meghan and Harry haven't yet visited the Duchess of Cambridge since she gave birth on Monday, so the brief reunion was a quick opportunity to hear a bit about the baby! William told reporters outside the service that the newborn is "behaving himself."

Meghan wore a conservative black ensemble for the occasion -- a stark contrast to what she'll soon be wearing as millions around the world watch her tie the knot on May 19. Little is publicly known about her gown, but she's reportedly gone in repeatedly for alterations as she's lost weight due to a pre-wedding "health kick."

The couple looked completely smitten during the Wednesday outing -- take a look in the gallery below.