She initially tweeted happiness for her ex-husband and his new legal wife after news broke they were expecting their second child together, but Sister Wives star Meri Brown may actually be hinting that she's upset over the news.

Did Christine Reveal The Sex Of Robyn & Kody's Baby?

Kody and Robyn announced they were expecting their second child together (the 18th overall in the family) two days before Father's Day--and when the holiday rolled around, a pregnant Robyn didn't hesitate to wish her husband a happy holiday on Twittter.

"Happy Father's Day @realkodybrown! You will always be a hero in my book because of your love and devotion to all of our 18 children!" she wrote.

Robyn Is Pregnant!

Likewise, Kody's second and third wives, Janelle and Christine, also took to social media to wish their husband a happy holiday.

"Happy Father's Day @realkodybrown. What an amazing engaged father you are! It says something when the older kids still seek your counsel," Janelle tweeted.

"Happy Father's Day @realkodybrown. Honestly, all of our children are blessed to have you as their Dad. #FathersDay," Christine added.

However, notably absent from wishing Kody a Happy Father's Day was Meri, who took to her Twitter account to wish a happy holiday to her father--but not her husband. a move that has caused speculation following the couple's recent divorce (a move Meri reports to have initiated to give Kody an easier time of adopting Robyn's other children) that Meri is especially hurting at the news that Kody is going to be a father again with Robyn.

Meri's struggles with conceiving another child after she had daughter Mariah 20 years ago has previously been addressed on the show, with her hesitancy to use Robyn as a surrogate back in season 3 becoming a big issue for her and Kody at the time.

Tags: Sister Wives TLC Reality TV