You'd been noticing recently that Tamaki has been acting a bit off around you, seeming to be much more overprotective than he had been. He's also, surprisingly, been going through mood swings as of lately. Another thing he's recently started doing was 'denning', something Alphas did when they found a potential mate as a means of courting said potential mate. Well, it turns out, that's all Pre-rut, and he's been rather clingy lately, wanting cuddles almost constantly.