There's A New Mystery On 'This Is Us,' & It Has To Do With Kate

This Is Us is happiest when exploring the mysteries of the past and the future. Season 4 has already dropped several reveals, from the introduction of Jack Jr. in the far future to the shock of Kevin and Sophie's marriage in 1998. Now the show has introduced a new mystery, that of teenaged Kate's boyfriend, Marc. Fans are wondering what happened between Kate and Marc on This Is Us? More importantly, why haven't they heard about Mark before now? Warning: Spoilers for This is Us Season 4 follow.

As viewers saw in Season 4, Episode 4, Kate and Marc did a meet-cute at the record store. He's the manager, and within a few minutes of meeting her, she becomes his employee. His undeniable attraction to her means fans aren't surprised when the two of them are next seen making out in the storeroom.

But then he turns up, uninvited to the Pearson big family dinner to celebrate Kevin and Sophie's marriage. As he explains to Kate, he realized that she would be the fifth wheel, since she said both Kevin and Randall were bringing home dates. So he pulled a Pearson like "grand gesture." He looked up her address on the job application, grabbed some daisies out of the neighbor's yard, and proudly introduced himself to the family as Kate's significant other.

But flash to the present, when Kate finds polaroids from that night, tucked away in the family's old piano bench. Rebecca sighs sadly upon seeing the photos, saying she was blinded by wanting to believe everyone was happy and moving forward after Jack's passing.

What is Rebecca referring to? There are some clues, starting with how Marc showed up.

Let's run through the series of events again, and this time, instead of looking through it through the lens of a "Pearson Grand Gesture," consider the facts. Kate's boss at work used his privilege to go into her personnel file, comes over uninvited, and trespasses in her neighbor's garden. After she introduced him as "a friend from work," he ignored her and told everyone he was her boyfriend.

Is anyone surprised Kevin's instant response to Marc was a resounding "NOPE"?

It's too bad Kevin doesn't have the words to explain to Kate why all of his alarm bells are going off. He tries to frame it as an age issue. (Marc is in his mid-20s, Kate is 18.) When that doesn't work, he tries to frame it as a gut feeling. But what he's trying to express is Marc's actions blew past Kate's boundaries.

On the surface, Marc and Jack look like the same over-the-top romantics. But this is the exact opposite of the patented Pearson grand gesture. Jack drove Rebecca across the country, sure, but he didn't force her to go or demand recognition as her boyfriend for it. He did it for her to make her happy. When Randall and Kevin make a big "grand gesture" of sending Kate the piano, it's one with her desires and happiness in mind.

Marc's "grand gesture" wasn't about Kate. It's about him, getting himself a girlfriend who happens to also answer to him at work. It's not romantic; it's a giant red flag.