It's not just about him wanting to bang before he leaves, he's talking about a summer romance. He met a girl over summer vacation, and he doesn't want to forget her after the vacation is done. "So tonight I hope that I will do just fine" is him saying how he knows this could be the last time he ever sees this girl, a girl he had true feelings for but has to leave to get back to his life elsewhere. "I don't see how you could ever be anything but mine" - He will always have feelings for this girl, knowing that she may be "the one who got away".
It's not just about him wanting to bang before he leaves, he's talking about a summer romance. He met a girl over summer vacation, and he doesn't want to forget her after the vacation is done. "So tonight I hope that I will do just fine" is him saying how he knows this could be the last time he ever sees this girl, a girl he had true feelings for but has to leave to get back to his life elsewhere. "I don't see how you could ever be anything but mine" - He will always have feelings for this girl, knowing that she may be "the one who got away".
@frostmyflakes31 I think your interpretation is right. I experienced this exact situation last summer
@frostmyflakes31 I think your interpretation is right. I experienced this exact situation last summer