I haven't written any stage directions, and I think I want to rework parts of it.
Setting: New Year’s Eve, 2002. A party. John and Susan are married. John is 30, Susan is 28.
John: Why’d you drag me here again?
Susan: Because it’s a fun party, and you needed to get out.
John: I was having fun at home. Besides, I’m a man. I should be able to decide when to get out and when to stay in.
Susan: John, you’d been in your big chair all day. What sort of woman would I be if I just let my husband sit around all day?
John: The sort of woman I married.
Susan: Did you meet the Davisons yet?
John: You introduced me to the Davisons three times now, honey. By now, they probably feel like they’re in Groundhog Day or something.
Susan: Really, John, another movie reference?
John: Well, it was a good one.
Susan: Yes, it was very good. Just don’t let it happen again. Come on, go mingle for a bit. It’s almost midnight, and the party will be pretty much dead after midnight.
John: I don’t want to mingle. I don’t know anybody.
Susan: And how can we change that? Mingling. Now, I’m going to get some punch. Why not take this time to get to know somebody. Who knows, you might find a new friend!
John: Okay, I’ll try.
Susan: Well?
John: Well?
Susan: Did you talk to anyone?
John: Oh, that.
Susan: Yes, that.
John: Yes, I talked to someone.
Susan: Who?
John: Well, there’s, um, there’s Matt over there. Matt and, well, Karen there.
Susan: Wait, I know him! That’s Doug Fiennes, from accounting.
John: Really? I could’ve sworn he said his name was Matt.
Susan: You didn’t even try to meet anyone, did you?
John: Honey, you know how I feel about introducing myself to people. It’s like I’m just
Susan: Just whoring yourself out for the night, I know.
John: Then why not indulge me, just a little?
Susan: This is something you have to get used to. You’re going to have to learn to get to know other human beings at some point in your life.
John: I know you. Isn’t that enough?
Susan: No. Now, come on!
John: Wait, sugar, there’s something I wanted to tell you.
Susan: And what’s that?
John: Just that I love you so much it’s disgusting.
Susan: Well, thank you. Now mingle.
John: Well wait, honey.
Susan: What now?
John: Isn’t there something you want to tell me?
Susan: Well, since you mention it, yes. I needed to tell you to that…
Party: 10, 9,
John: Wait, it’s starting!
Party: 8, 7,
Susan: Now I have to say it,
Party: 6, 5,
Susan: John, I think you should
Party: 4, 3,
Susan: know that
Party: 2, 1,
Susan: I’m not coming home with you.
Party: Happy New Year!
John: Happy New Year, honey.
Susan: Don’t you care?
John: Wait, what did you say?
Susan: I’m not coming home. It’s over.
John: Can we discuss this at home? This really isn’t the place.
Susan: This is the only place and the only time to tell you. It’s 2003 now, and do you know what day it is?
John: New Year’s.
Susan: It’s also our anniversary.
John: Yeah, that too.
Susan: Don’t you get it, John? We’ve been married seven years today.
John: So why don’t we at least shoot for ten? Come on, let’s just go home and talk about what’s going on.
Susan: John, I’m serious! Seven years!
John: And now our bad luck is over for that mirror plate we dropped at the reception, right?
Susan: I’m not kidding. Do you remember high school biology?
John: I don’t see what that has to do with anything.
Susan: Do you remember it?
John: Well, I didn’t really pay attention, but sure.
Susan: They said in high school biology that it takes the body seven years to replace all its cells.
John: Okay, but what’s your point?
Susan: If we’ve been married for seven years, then all of my cells have been replaced now.
John: So my wife is all shiny and new. Isn’t that great?
Susan: I’m not your wife! Don’t you see? The body of your wife is gone! The woman you married has been replaced by now.
John: Wait, you want to leave me because you have new cells? That’s the dumbest thing I’ve heard all night!
Susan: It’s not dumb! It’s true. You married Susan, but that’s not me. I’m a single woman who’s going to go out into this world and experience it for herself.
John: Okay, let’s assume for the moment that this is true.
Susan: It is!
John: Fine, it’s true. You’re a different woman. You’re about to go off into the bright new world around you and do what?
Susan: I don’t know. Maybe I’ll meet someone new.
John: What, to match the new you?
Susan: Exactly.
John: Do you really believe this?
Susan: I wouldn’t say it if I didn’t.
John: Then I can’t stand in your way, can I?
Susan: I’d rather you didn’t.
John: Then you can stay in the house. I’ll move out. Now, at least let me take you over there.
Susan: I’ll drive myself back. I don’t want to ride with a stranger.
John: Funny, Susan.
Susan: It wasn’t meant to be.
John: Is that why you wanted me to mingle so much? You wanted me to get to know someone who could give me a ride after the party?
Susan: I told you it was important.
John: So, I guess I should be thanking you for that.
Susan: Don’t make this harder than it already is.
John: How hard is it already? You seem to be going about this whole thing with relative ease.
Susan: Don’t think that I haven’t cried about this, John. You’ve been great to Susan, and I’m grateful for that. I just hope I can find a new man as good as you.
John: Shut up! Don’t try to sugar-coat your betrayal.
Susan: I’m not betraying you. It’d be betrayal if I permitted you to live with a woman you didn’t even know. This is what’s best for both of us.
John: Fine, get out of here. I don’t even know why I married you!
Susan: You didn’t. You married Susan.
John: I said leave!
John: Susan, wait.
John: I said wait, Susan.
Susan: I’m not Susan anymore.
John: Well, whoever you are now, wait! I thought of something.
Susan: What?
John: Everybody’s cells are replaced after seven years, right?
Susan: That’s what I said.
John: That means my cells, too.
Susan: What do you mean?
John: You’re not the woman I married, but I’m not the man you married.
Susan: Yes, I understand the concept.
John: But you don’t, really. If neither of us are the people who were married seven years before, then we’re both new to each other.
Susan: Oh.
John: This is it. This is the first time we meet.
Susan: I think I see. Let’s make it count.
John: Hi, I’m John Stevens.
Susan: I’m Susan.
John: Susan. That is a lovely name.
Susan: Thank you. I like John, too.
John: I’m glad you do. Will you marry me?
Susan: Yes!