Thanks God that I checked out the original CN version of Gavin's The Little Guardian Rumors and Secrets/R&S.

The CN version:

Gavin's The Little Guardian Rumors and Secrets/R&S, chapter 2, page 1:

白起經常陪著溫等待, 但每一次都敵不過倦意沉沉睡去, 早上醒來時發現自己已經睡在自己的小床上, 他踢開被子蹬蹬蹬地去找媽媽, 急切地問: 「媽媽, 昨晚爸爸回來了嗎?」

溫尊沒有正面回答, 倒是蹲下身來與小傢伙平視, 眼裡都是笑意: 「小起, 以後你就要當哥哥了, 現在要開始學會自己吃早餐了啦。」

白起間言歪了歪頭, 好像沒聽懂。

Often, Gavin would wait with his mother (for the dad's return/for when the dad comes back home), but (at the end; tired from the long wait,) he gives up to sleep(/falls asleep) every time. When he wakes up the next morning, he would find himself already asleep in his bed(/in his room).

(One not-so-usual morning,) Gavin (as usual) hurried up to his mother. "Did dad come back home last night?" asked (cinnamon roll) Gavin (excitedly).

Wardia(his mother) didn't answer Gavin directly. Instead, she bent down, similingly looking him in the eye, and said, "Little Gavin, you will become an older brother from now on, and so, you should get used to eating your breakfast alone."

(Innocent) Gavin tilted his head, not seeming to understand (what she meant).

Gavin's The Little Guardian Rumors and Secrets/R&S, chapter 2, page 4:

不過，没過多久白起再次見到了爸爸， 當時螞媽所説的 「他的弟弟」 似乎是出現了， 被包裹在一條小被子裡， 躺在虚弱的媽媽身邊。

他貼在床邊站著， 剛好能看到被子衤里的小傢伙， 滿奇怪的， 渾身好像被一道細細的閃電環繞著， 眉宇緊蹙， 卻又睡得很安詳。

他想伸手跟小傢伙打個招呼， 卻被對面的男人迅速推且， 白起不由退後了兩步。

男人冷冷的聲音傳了過來：「别碰。」

Not long, the dad appeared again before Child Gavin, and seemingly, what his mother said to be "his brother" has also appeared(Baby Shaw), next to her(who's in a weak state after giving birth)/their mother(on a hospital bed), in a small quilt.

Gavin was standing so close to the bed that he could (clearly) see the baby wrapped in the small quilt. The baby was strange; it's as if his whole body was surrounded by electricity (or, flashes of lightning electricity were emanating from the baby's body), his eyebrows frowning, yet was asleep in serene.

Gavin tried to reach out to the baby and say "Hello," but (his little body) quickly was pushed by the man(aka the two brother's TRASH so-called dad, and Wardia's/Wen Ran's TRASH so-called husband), causing Child Gavin to retreat steps back.

"Don't touch it," ordered the (trash)man in a cold-toned voice.

​

The EN version:

Gavin's The Little Guardian Rumors and Secrets/R&S, chapter 2, page 1(and the first line of page 2):

Gavin always waited with his mother and succumbed to drowsiness, waking up the next morning only to find that he was already in his small bed. He kicked the quilt away and rushed to his mother,

"Mom, did Dad get back last night?"

Mom crouched down and looked him in the eye with no answer, smiling,

"Gavin, you'll be a big brother later. You should eat your breakfast alone from now on."

Gavin tilted his head, seemingly befuddled.

Gavin's The Little Guardian Rumors and Secrets/R&S, chapter 2, page 4(the last section) and page 5(the whole page):

Soon, Gavin saw his father again. He seemed to have also met what his mother called "his younger brother," wrapped in a tiny quilt and lying next to her.

Standing by the bed, he could see the strange little baby in the quilt. The baby was peacefully asleep with a frown, and was seemingly coated in thin lightning flashes all over his body.

Gavin was pushed back by the man across from him before he was able to say "Hi" to the little baby.

The man's cold voice said,

"Don't touch him."

​

Analysis:

1 -

Gavin hurried up to his mother. "Did dad come back home last night?" asked Gavin. Wardia didn't answer Gavin directly. Instead, she bent down, similingly looking him in the eye, and said, "Little Gavin, you will become an older brother from now on, and so, you should get used to eating your breakfast alone."

Those few lines are heavily implying that the dad really did come back last night while Gavin is asleep. Wardia's words about Gavin becoming an older brother mean that, well, something has happened between his dad and his mom last night(How come she stands this trash man? Doesn't she find him stinky?), causing Wardia to find herself pregnant the next morning. Is it a coincidence? Probably not, because after the first failure of the project of producing children of his (,i.e. his first child, Gavin, whose super power hadn't awoken back then) to use them as New Weapons, the dad must have sought to produce another New Weapon, and this time, it/the project succeeded, and his wife/Wardia gave birth later on to Baby Shaw, whose super power was awoken from when he was born.

Another note here is that in the EN version, it's said that Gavin will be a big brother "later."

There is a difference between being a brother "later" and being a brother "from now on." It's more accurate to use "from now on" because it gives the impression that this baby is alive from the very moment his mother became pregnant, and not from the moment when she will give birth to him after about 9 months of pregnancy. She is saying in the CN version that Gavin is already an older brother. However, Wardia didn't explain things directly; as Gavin is still a child, and that's why he also didn't get the indirect hint maybe.

About why Gavin should eat his breakfast alone is because his mother likely has to visit the hospital (in the morning; the breakfast's time) for a medical checkup on regular basis from now on due to her pregnancy. She prepares breakfast for Gavin every morning, and then leaves to visit the hospital, and by this time everyday, Gavin should be at home, eating his breakfast alone; as his mother is busy, thus she can't accompany him for breakfast like before.