It's the little things that made Victoire fall in love with Teddy.
He has a small lock of hair behind his left ear that is always bubble gum pink. Harry said that that was the color Teddy's mom usually stuck with for her own hair. Teddy doesn't realize he does it.
Whenever he's happy, like really happy, his eyes change to the same shade of green as Harry's. Again, he doesn't realize it.
He wrinkles his nose when he is hiding something. He tries not to, but Victoire always notices it.
He always holds the door open for whomever he is walking with before walking through the door himself. Ron said he got that from watching Victoire's own parents interact.
He can always calm Victoire down when she's having a 'crazy fit' as he dubbed it when she was six and he was eight. Victoire got stressed over the smallest details. Headmistress McGonagall had Teddy floo to the school to calm her down after breaking her favorite quill days before she was to take her N.E.W.T.S.
He was very passionate about everything he did, until he got bored. He started Hermione's old club back up as a second year, got loads of people to join, then quit the next year because he wanted to start a Wizard's Chess club, which he quit just after the third official tournament.
He was ambidextrous, but he chose to favor his left hand because being right handed was too common.
He kept two photos in his wallet, one of his parents, the other of Victoire.
He liked to drink hot chocolate just before bed because it gave him the craziest dreams.
For some, his train of thought was difficult to follow because he jumped around a lot, but Victoire found it made for an interesting conversation.
His biggest fear is his parents not being proud of him.
He was frightened Bill would hate him when he asked for Bill's blessing to date Victoire. And again when he asked Bill for his blessing on marrying Victoire. Once more when Teddy and Victoire told the family they were expecting.
While other boys lusted after Victoire for her looks or brains, Teddy fell in love with her because he knew she was actually really insane-in a good way.
These are only a few of the little things Teddy did to make Victoire fall for him; she found a new one everyday.