Seamus exhaled quietly, mouth open, as he tried to formulate an answer to Dean's question that was more constructive than 'she's a cow'. "Because she doesn't get it," he eventually spluttered. "She doesn't know what it's like. Not that I -" He'd only experienced Dean's PTSD from the outside, of course he couldn't know what it was really like either, but he had his own war demons to wrangle. "All future potential girlfriends - or boyfriends - should have to sit through at least one Battlescars meeting. Not to hear you speak or anything. Just so they have some idea what we talk about - what we deal with." It wasn't a particularly practical suggestion, but Seamus didn't know what else would help. There were some Slytherins he still wasn't on the best of terms with (Parkinson, Goyle) but he couldn't imagine even them shouting about Dean's PTSD in public. And if they did, at least it would be deliberate and not out of pure thoughtlessness.
He gave a non-committal hum to Dean's comments about Susan. He was torn between wanting to keep her in check for Dean's sake and wanting to go whisper suggestions about banshees into her ear. If anyone deserved them it was Ophelia. "Always want you around," he said, deciding that talking about egging Susan on probably wouldn't help. As for the no Valentine thing... it wasn't so different from previous years. He'd just let himself have An Expectation, which was clearly a mistake. He'd take better care in future.
Grumbling as he shifted, Seamus sat up a little, his back to Dean's chest so they were still connected. "You just want it all, don't you?" he teased. "Real blanket, Seamus-blanket, cake." He summoned the cake over with a fork they'd have to share. "Supposed to be a proposal cake," he explained. He'd taken the cake topper off when it arrived, so it was no longer obvious. "She said no. So at least some poor guy's having a worse Valentine's than we are. I hope it's not Ron." He didn't really think it could be. For a start, why would Hermione say no?