Harry: He freezes for a moment then breaks out into an insanely happy smile.
Ron: He hugged you as tightly as possible while smiling uncontrollably.
Draco: He lifted you up by your waist and spun you around, then kissed you when he set you down.
Neville: His face went pale and he stuttered momentarily before he kneeled down and kissed your stomach.
Fred: He jumped around in a circle doing a happy dance like a dork.
George: He stared at you and laughed, thinking it was a joke at first, he then proceeded to realize you were telling the truth and then kissed you.
Marauder's Era & Tom & Newt
Sirius: He was so excited that he somehow managed to run into a door that James was opening and knocked himself out.
James: He smiled brightly and proceeded to brag to everyone about his accomplishment.
Remus: He fell to his knees and began to cry, you sat with him and he informed you that while he was in fact worried, that he was very happy.
Peter: He held your hands while you both jumped up and down together, showing your happiness.
Tom: He kissed your forehead and told you that he was glad, then continued on with his day.
Newt: He passed out where he stood and hit the ground.
Regulus: He hugged you and kissed your shoulder gently, instantly becoming more gentle with you.