Lyric discussion by beautifulxgoodbye 

Cover art for Ours lyrics by Bravery, The

this might just be my own little warped personal meaning, but i interpreted the song as referring to a one night stand kind of ordeal. except not. they're together for a night, but there's more feelings involved than he wants to admit. so he sings about it. (and when i say he, i'm referring to the singer, regardless of whether it's his own experience or not) especially when he sings, "After tonight,/ who knows where we'll be tomorrow/ what if we're never here again?". it's a one night thing, so they've got to make the best of it. but it's somewhat concerning, as he sings about "already miss[ing] you, even as you're lying next to me" = feelings. but perhaps 'she' (i'm assuming) only sees this as a hookup and for that he must make the best of the night and enjoy it while he can. they might not be together later, but they are for now.