Eric Trump and his wife Lara welcomed their first child into the world this week, and the new dad already got a crash course in diaper shopping for bringing his little boy home to meet his new brother: their dog.

The 33-year-old son of President Donald Trump took to Twitter on Wednesday evening to share a photo of CVS's diaper selection, just one day after Lara, 34, gave birth to their son, Eric 'Luke' Trump.

'Yup. This just got real!' he tweeted, but someone else managed to capture the dumbfounded expression on his face as he perused the selection.

Need help? Lara Trump took to Instagram on Thursday to share a comical photo of her husband Eric looking confused while diaper shopping for their baby boy Luke the night before

First-time parents: 'Maybe the greatest picture ever,' she joked, using the hashtag #LifeJustGotReal

'This just got real': Eric tweeted a photo of the diaper selection while shopping at a local CVS on Wednesday evening while Lara was still in the hospital

The next day, Lara posted the picture of Eric looking beyond confused on her Instagram page, writing: '#throwback to last night. And, maybe the greatest picture ever #LifeJustGotReal.'

The new mom was still in the hospital when Eric was shopping for diapers, so the photo may have been taken by a Secret Service agent who was amused by the dad's confusion.

The picture sees Eric standing in front of the drug store's diaper selection with his mouth slightly open and his hands in his pocket, as if he doesn't know where to start.

Sporting typical dad attire, Eric was casually dressed in khaki pants, a half-zip sweater, loafers, and a baseball cap for the evening diaper-run.

Look of love: After bringing their baby boy home from the hospital, the couple shared an adorable photo of their rescue dog Luke staring at the little boy

'Brothers': Eric tweeted that Ben 'can't stop staring' at the newest addition to their family

Proud parents: Eric and Lara have shred plenty of photos of their new son this week

Eric and Lara are already proud parents, and they have both shared plenty of photos of baby Luke.

However, one of the cutest images sees the newborn with their dog Ben, whom Eric has affectionately referred to as Luke's 'big brother'.

Both he and Lara shared a heartwarming snap of of the pup sniffing Luke's face while the baby boy is asleep on his father's legs.

'#BigBen loves #LittleLuke! Ben can't stop staring at him! #Brothers #BestFriends,' Eric tweeted, while Lara captioned the picture 'Best Friends' on Instagram.

Luke is the ninth grandchild for President Trump, and Eric proudly announced the news of his birth on Twitter on Tuesday.

'Little Luke'; Many of the photos were taken right after the little boy's birth

Proud: Eric happily shared the news of Luke's birth on Twitter Tuesday, just a few hours after they welcomed their son into the world

Happy news! While announcing his birth, Eric shared this photo of the baby, revealing his name is Eric 'Luke' Trump

Father and child: The doting dad also posted this black-and-white picture of himself with his newborn son on Instagram

'@LaraLeaTrump and I are excited to announce the birth of our son, Eric "Luke" Trump at 8:50 this morning,' he wrote, less than four after the newborn's arrival.

The new father also shared a sweet picture of his son with the world, posting the adorable image alongside his tweet.

In the picture, the tiny newborn appears to be sleeping soundly in his mother's arms, with just her hospital gown visible in the background.

The image shows the little boy wrapped up snuggly in a blue, pink, and white hospital blanket, with a pink woven cap on his head.

Eric then shared a second picture of his child on Instagram, this time a black-and-white photo which captures himself cradling Luke and dropping a sweet kiss on his forehead.

Growing family: The baby is President Donald Trump's ninth grandchild. Eric and Lara are pictured in July

Excited! Eric's father took to Twitter a few hours after the announcement to share his joy at the happy news

'I can't wait to meet you': Eric's older sister, Ivanka Trump, congratulated the new father on Twitter

'Older brother revenge': Eric's brother Donald Trump Jr. shared a more humorous message

Eric's father shared his congratulations on Twitter, posting a message to the couple online a few hours after they shared their own announcement.

'Congratulations to Eric & Lara on the birth of their son, Eric "Luke" Trump this morning!' he wrote on his official account, while retweeting his son's original post.

Eric's older siblings, Donald Trump Jr. and Ivanka Trump, also both congratulated the new dad on Twitter.

'Welcome to the world, baby boy. I can't wait to meet you,' Ivanka wrote, while his older brother shared a more humorous sentiment.

'Congrats buddy. Welcome to the club. Now that the niceties are out of the way it's older brother revenge for that drum set to my kids,' Don Jr. tweeted.