Watching him from the corner of her eye, Seras was for the most part relieved that he didn't pester. But then there was teeny little something in her gut that made her feel kind of bad for reacting so suddenly, and in the end, that irksome gut feeling won out, which would explain why she forced herself over to him.
"Er...excuse me," she announced shyly, bringing her hand up to her neck. "I didn't mean to spoil your fun like that. I realize how I reacted was a bit out of line, but you did give me a bit of a fright there and--um, well I'm sorry."
Nibbling on the inside of her cheek, Seras waited for his response, slipping her hands in her jean pockets. He'd accept her apology or he wouldn't, but either way he'd probably still think she was completely off her rocker.