OK single dopers. The holidays are here and we can pretty much all count on hearing this question at least once. Let us share our favorite retorts.
I usually say simply: Because no one will have me.
Not particularly clever, but it usually ends the conversation. How do you like to respond?
I do have a certain amount of taste. I could never marry any woman who’d have me as a husband.
Or:
Nobody ever liked me that much.
Or:
[Head-butt] That’s why!
The priest won’t let me back in the church after the incident with the cow.
First you get the money, THEN you get the power, THEN you get the women. See what happens when you do it out of order? You end up with something like YOUR marriage, that’s what…
Of course, I never have the actual balls to say this. But that’s what I’m thinking.
I’m married, so I may not count.
My wife and I lived together for a few years before marrying. I would get the “When are y’all getting married” question every time we visited my folks.
I wanted to say “knowing we’re sinning makes the sex way hotter!”
But being the polite son that I am, only managed to croak out a meek “I dunno. Maybe sometime soon.”
I just change the subject and point out how pregnant my sister is. With all the girls in my extended family, everyone immediately forgets about me and heads straight to her to talk about the baby.
[hijack]
Honestly, the way my mom is, I’d rather be single around her. She’s scared away many guys by “accidently” calling them my fiance or husband and talking about future grandkids or how great my first name would be with their last name. And she’s been doing stuff like that since I first started dating, at 17.
[/hijack]
" Why, Uncle Albert! Because I haven’t met a younger version of you, of course !"
" If I do get married, dear, I promise you you’ll be the first to know. "
[/Miss Manners]
My all time favorite answer is a question.
“Why are you asking me that question?”
Some of the runners up are:*
“Why, are you proposing? You’re my (aunt, uncle, cousin, whatever). That’s disgusting!”
“Because I’m a big ol’ flamer.” (Always takes em a few to figure that one out)
“When are you getting divorced?”
*And yes I have said these things to relatives. I can be like that when I want to.
100% of recreational time spent as Game Master for “Yugioh” doesn’t afford many opportunities to meet hot babes.
Recumbent bicycle not quite the chick magnet I imagined.
Learned flannel is fashion “don’t” too late in life.
Fiance broke up with me after my pre-nup suggestion offered over Chicken McNugget dinner.
My only love is unrequited.
I’m too handsome and people are women intimidated. Yeaaah… that’s the ticket!
‘Do you have Need To Know?’
Generally I respond with something like, “I dunno, I guess I just haven’t found the right person.” What I really want to say is, “What are you talking about? You were at my wedding! Was it really so horrible that you don’t remember?” And run away sobbing.
Because you touch yourself at night.
Oh wait. That’s how to emotionally scar your childern…
“I’m not married becuase you people won’t stop bugging me about it”
This is brilliant. Not only will I never be asked that question again, but I wouldn’t be invited to any gatherings where it might come up. I’m not enough of a misanthrope to use this yet, but give me another year or two…
Generally my girlfriend and I just shrug the question off. If her family asks me, I just say “ask her.” If my family asks her, they get “ask him.” In my family, I have to deal only with my mom. We made a deal years ago - I answer her questions about relationships honestly (more honestly than she’d like, sometimes) and she makes sure nobody else in her family asks. It works great.
I’ve never been asked that question. Either people are more polite in Australia or I’ve been being subtly insulted all these years…
“I’m married to the sea.”
Maybe your family thinks the answer is just so obvious there’s no need to ask. 
Just think of the scene you could make at your next family gathering Silentgoldfish! What you do is, just burst out crying and say: “How come nobody in my family never asks me when I’m going to get married? Do you all think I’m so hideous and such a social pariah that it’s never gonna happen, so why bother asking? Why does my family hate me so much!” Then run screaming and crying from the room. You’ll be a legend in your own family. You’ll be talked about for generations. They’ll “forget” to invite you to future gatherings! It’s all so win-win for you either way.
Or, just go around head-butting relatives. I really like this one. Thanks to Johnny L.A. I may have a new addition to my repetoire.
Because I am Gay and despite the fact that you have been married and divorced eight times*, you still piously vote with the idiot masses to protect the so-called “sanctity” of heterosexual marriage.
(*Yes, my brother has been married eight times.)
Why aren’t you married yet?
I’m a librarian, it’s part of the job description (right along with the bun and the granny glasses).
I am.
Oh, what, you weren’t told?
“Well, Mom, I haven’t met the stripper I want to settle down with yet.”