"Hyung, don't get hurt! I love you~" - 2016

"During activities this time, please don't get hurt! I love you!" - 2017

Jeno always wrote this in his letter to Mark. seeing how busy Mark had been since debut might have worried Jeno because he was being overworked too much

from the debut of NCT U-NCT 127-NCT DREAM in 2016 to the comeback of NCT 127-NCT DREAM with the High School Rapper filming between them in early 2017

any normal person will definitely feel very tired from all those activities...

despite all those activities, Mark never showed that he was tired...

Jeno once said Mark's good at lying. maybe this is one of the reasons why he thinks like that

bcs Mark was Dream's leader, so he had to be a good example to his dongsaengs because everyone looked up to him

when the other members wrote love letter mostly to their family & fans, Jeno wrote this letter just to tell Mark not to get hurt, how much he respected him for always working hard and also tried to cheer him up by saying that he's more no fun than Mark

Jeno even said that he wanted to switch bodies with Mark because he wanted to know how tiring it was to be Mark since he always did a lot of activities, so he could determine how well he should treat Mark

so if you see him being extra soft & gentle to Mark, now you know why..

for Mark who's always kind, supportive, positive, works hard, likes to help, leads and treats him & Dream well, being a good example for his brothers, Jeno is always very thankful for that.

and for the small things Mark did to him such as giving him a birthday greeting right at midnight despite being far from him and also asking for his whereabouts by calling him/sending texts bcs Jeno rarely replied on kkt, Jeno felt touched and grateful because of that ;_;

that's why it was really hard for him to write and record Dear Dream, because it was for Mark. Jeno said that he wrote the lyrics with the thought of how much Mark means to him and Dream...

when Mark graduated from Dream, he didn't really cry but still it was a sad thing for him. he said before his graduation, he always wondered how Dream would become without Mark. for him, Mark really has an important role in their team...

you see his expression when he kew Mark couldn't come to their first concert? he was a lil bit sulky, but he couldn't do anything either because Mark's schedule clashed with their concert...

it's actually sad, because Jeno had always said he wanted to have a unit with Mark. when Mark left Dream, he told fans not to worry because they're still NCT and could still meet often. but Jeno himself also said he rarely met with Mark last year because he was very busy

so to summarize it all, Jeno really has a lot of love for Mark and he never even hesitated to express it

he always showered him with lots of affection whenever they met again...

every time NCT gathered together, most of the time they were never far from each other

it's to the point that he feels happy just by seeing Mark's face

back in 2017-2018, almost every answer to the questions given to Jeno was Mark

it makes you even wonder if Jeno has MLS (Mark Lee Syndrome)

he even looked happy just by hearing Mark's voice over the phone after a long time...

and remember when the Dreamies were told to roast Mark, they were so quick to roast him meanwhile Jeno didnt show up until later he randomly typed "I love you"

and only after that he joined the others to roast Mark about his eggs

Jeno, your crush is showing :((

Mark finds Jeno as someone who's reliable. I'm sure he also felt thankful to Jeno for taking care of him while he's in Dream & taking caring of Dream when he's not around. so it's not surprising that he kinda gave the leader position to Jeno

Jeno gave him lots of praise, support, love and trust

so it's understandable if he also does the same for Jeno

if you look at their interactions, you can tell how Mark is also so fond of him. he loves babying him because well... Jeno is a big clingy baby

the way he talked to Jeno was so cute here :((

Mark's little smile when Jeno said he missed his friend 'Mark' :(

and Mark's soft smile when Jeno hugged him so tightly with his big smile :(

Mark said he found it cute how Jeno's facial expression could not lie, because what he felt inside would appear on his face

when Haechan said Mark cried in Jeno's arms because he was touched Jeno was the one who gave the trophy to NCT 127 when they won on The Show :"(

a baby babying a baby

if you look at the tweet at the top and the video below, you can see that it's not really uncommon for Jeno to say "I love you"

Jeno usually said it as a way to express his thankfulness to Mark and when he wanted to encourage him

but for some reason, Mark still found it surprising when Jeno said that. well everyone did

Jeno to Jisung: I love you
Mark: ohhh my goddddd

when Jeno texted him "I love you" out of nowhere, he was also very shocked. Jeno also didn't reply him after, so he thought it was a confession. later he decided to write it as his TMI

Jeno was taken aback & had to explain that it wasn't like what Mark had thought

but isn't that a very Jeno thing to do?

he often does or says random things all of sudden, then makes people confused, but most of the time he will not explain why he did it

like this one

although maybe Jeno doesn't say it often, but everyone with eyes can see how much he loves you, Mark

he likes it when you're around :(

after all, you've always been one of his most favorite person

from the trainee days, Mark said that he and Jeno liked to measure the size of their hands together. they found it interesting because their hands are exactly the same size

when Jeno was a trainee, he felt a bit threatened by Mark, bcs he was stronger than him

once when Mark piggybacked Jeno, he almost flew

but eventually, Jeno grew to become one of the strongest in NCT Dream. Mark was even impressed by his strength.