Age and marital status

When you are young an people ask you are your marital status, the straightforward answer is one of the following:
1. I'm single
2. I'm married or attached....

That's all Fine until you get older.

I'm single or I'm still single seem to sound strange.

What would be the ideal phrasing to convey the message ?

How about :
I've never married. Seems more appropriate for older folks.

What do you think ?