Theseus has always been overpotective of his borther, even more so after Leta Lestrange. Naturally he wants to check that this Tina Goldstein is good for his little brother. Percival is a protective boss, who kind of adopted Tina and Queenie as his sister after the Grindelwald fiasco. So naturally he wants to check on this Newt Scamander and see he won't drag Tina into any more trouble. During all this checking, Percival and Theseus meet. They start standoffish but after multiple encounters start to fall for each other.

Bonuses: Tina and Newt are relieved. Their meddling was starting to get on their nerves.