"take your seats and I'll write the next line" should read.
"take your seaside arms and write the next line" It's a reference to a passage in Nabokof's Lolita where he describes her as having 'seaside limbs and ardent tongue' A girl he fancied loaned him the book and he put it in the song so she'd know it was about her. She didn't have a clue. Too vague Gary, perhaps you should have just told her.