This Is Us Season 4 finale: How are Kevin's twins so much younger than Jack Junior?

There was one thing at the end of Episode 18 of This Is Us Season 4 that really confused people, Kevin's children coming up to him while Rebecca is on her death bed.

This Is Us Season 4 has come to an end and there were a lot of twists. Episode 10 called "Strangers" became the most-watched episode since September 2019 and saw a 21% increase in viewers aged 18-49 over the previous week, according to NBC.

The episode started with Jack Junior (Toby and Kate's son, not really 'Junior') singing to his unborn baby, then came some new characters including Jack's "adopted" sister and Madison's gynecologist and his daughter. The finale of This Is Us Season 4 was filled with new characters and they will probably become an important part of the show as it unfolds in the upcoming seasons.

But there was one thing at the end of the episode that really confused people, Kevin's children coming up to him while Rebecca is on her death bed, which many fans are thinking is on the same timeline as of Jack having a baby.

Since Madison told Kevin about the pregnancy on Jack Junior's first birthday, the twins must only be 1-2 years younger than Jack. But Kevin's children were almost 10-11 years-old in the scene while Jack Junior from the future looks much older and about to have a baby.

The scene has left many people confused and #ThisIsUs on Twitter is filled with similar tweets.

Now a plothole this big is not 'This Is Us-style' so there's definitely something else going on here. One theory could be that Jack having a baby and Rebecca on her death bed are two different instances and at different points of time in the future. This one is actually more believable since the showmakers like to play around with different timelines while narrating the story.

Another theory is that Madison is not the mother of twins showed in the scene where Rebecca is on her death bed. While this is a little less believable because in the 18th episode of This Is Us Season 4, Kevin's daughter was shown when Madison tells him that they are having twins. And also it's a bit unconvincing that Kevin got another girl pregnant, that too with twins. (And no they aren't Kevin's grandkids if you are thinking that, his 'son' called him Dad in the scene.)

What do you think about these two theories which could unfold in This Is Us Season 5? Let us know in the comments below.