Obsessed by the cuteness overload.

Gun is rough and quarrelous to everyone. From his boys, to his former team-mates, he has a bad temper and everyone is afraid to piss him off. In "Fish Playing in Secret Chamber" (which I skimmed only for him and mentions of his 'young girlfriend') Ai Qing recalls how Gun used to quarell with them all the time, and even notes in the present how he has a bad temper and how on earth could he have a girlfriend.

But while watching the drama, I noticed Gun really doesn't yell at Squiddy or treat her roughly. At the start, in the cafe, he was impatient. After, during their two other meetings, he's trying to get to the bottom of things, but he takes care of her feelings.  He even says how he doesn't want to embarrass her or hurt her feelings. Guaranteed, that was more for the impact on his boys, and out of consideration for her age, though. His personality is one that he never cared for anyone's feelings. Only his grandfather (whom he riles anyway), his mom/aunt and his Xiao Bai, are people whose feelings he'd consider before scolding them.

Later on,  when they start the relationship, he goes out of his way not to hurt her feelings. Even when they quarrelled, he moderated his tone of voice. That quarrel was super funny to me because he ran away. The only time he was really harsh was when they broke up the second time, and he was trying to be responsible and leave the little kid alone - which he failed at.

I saw the sweetness because I'm deliberately looking for it and ignoring anything else. Am I right? Did you guys notice anything different or similar too?

I noticed the same things. Nian Nian changes him, for the better. He wouldn’t have been so harsh to her if it weren’t for her mother’s interference...I can’t stand her mother, but love her father. :)