Seamus' silent wish is that Harry ends this war before Christmas, and the stitching is not super quality because he doesn't know how to sew well with magic. The bear says "Yaaaaaay" in a low-pitched voice when hit with magic. He isn't impressed, he's sure this is going to turn to shit soon, but he isn't creeped out by much. He'll disarm the bear, he'll use calming charms to try and sedate it, try to make it sleep, tickle it, perk it up, etc.
He is wary of Megan's bear being named Queen Elizabeth.
He does ask if they have to take the bears elsewhere or if they stay in the classroom.