It seems like Jackson (Jesse Williams) and April (Sarah Drew) will unexpectedly bring a plus one during Owen (Kevin McKidd) and Amelia's (Caterina Scorsone) wedding in the finale of "Grey's Anatomy" season 12.

Based on the trailer for the upcoming episode, the elegantly dressed April will unexpectedly go into labor as she prepares to attend her friends' wedding. But Jackson is nowhere in sight. Good thing Ben (Jason George) is there to help her deliver the baby.

But even if Jackson was not at his former wife's side during her labor, Williams told TVLine that his character is happy about the arrival of the new baby.

"Just them even [expecting] a child that, by all appearances, is healthy," Williams said, adding that the pregnancy "was an incredible milestone for them... and an incredible sigh of relief."

The former couple did not expect to have another child after they decided to go on separate ways when their marriage nosedived when their first child died shortly after being born. This gives Jackson and April a sense of achievement.

"Their relationship may not have worked, they might have stumbled along the way, but they did accomplish something. There is a silver lining that kind of buoys them," Williams stated.

But while Jackson and April have something to look forward to during that time, Amelia seems to be having cold feet just before she walks down the aisle.

A separate sneak peek shows that Meredith (Ellen Pompeo) and Maggie will force Amelia to step out of her room during her wedding day. But even her closest friends cannot help her shake off the anxiety that Amelia feels right before she gets married. This prompts Owen to come to Meredith's house to talk some sense into his bride and push through with the wedding.

"The Grey's Anatomy" season 12 finale airs today, May 19, on ABC.