[Grammar] Sloppier or more sloppy?

[Mori]

I just saw the following quote:

Bad handwriting? Keep this in mind: more intelligent people tend to think faster, and as a result their handwriting is more sloppy.

I can't find more sloppy in any dictionaries. Does it sound OK to you native speakers? Since it ends in y, shouldn't it get -er, like happy > happier? Is there a grammatical rule, or is it simply an exception?

 

[Rover_KE]

I can accept both 'sloppier' and 'more sloppy'.

 

[Skrej]

'Sloppier' is natural in AmE.

I'm not too bothered by 'more sloppy', but I still prefer 'sloppier'.

I also have a sudden hankering for sloppy joes.

 

[andrewg927]

Skrej, do you prefer more sloppy joes or sloppier joes?

 

[Skrej]

I like the sloppiest joes I can get.

 

[andrewg927]

More sloppiest joes to you, Skrej. Mori will have lots of fun with his or her students.