Hiya, once again looking for a fic.

Martha tricks Lois into believing that Clark has a girl friend, but no wardrobe and needs fashion tips.
So Lois goes shopping with him for suits (the jackets are too small and the trousers too wide, accounting for his normal unfitting suits) and stuff and comes to find out that she really likes him.

Any tips would be appreciated.

I believe you are looking for "Date by Arrangement" by Wendy Richards.

It's a good one, I may end up rereading it myself!

Thanks, that's it.