A custom text byline under posts?

I want to create a new text field below the post title, where the byline/ingress should be. For example:

MAN WETS HIMSELF IN PUBLIC
Police now raises bed wetting-awareness <--- This text!

Blablablabla

*footer*

So... basically I want a second title with smaller text but still high SEO (not as high as the title obviously). Is this possible? How do I do it? Any good plugins? Can I change it in atahualpa somehow?

Thanks!