Might sound dumb but does anyone know if a cake covered in mmf be put in the fridge?

I wouldn't suggest it. The condensation from being in the fridge, then taken out will cause your MMF to show water "drops".

Fondant covered cakes can be successfully refrigerated.

When removed from the fridge, it's important NOT to touch any spots of condensation as they will evaporate on their own without leaving marks...

http://www.cakecentral.com/cake-decorating-ftopict-611510-.html

HTH

Hi and Welcome to CC, AfordRN.

Decoding CC acronyms:

http://www.cakecentral.com/cake-decorating-ftopict-2926-.html

Everything you ever wanted to know about baking, assembling and decorating your 1st tiered/stacked/layer cake:

http://www.cakecentral.com/cake-decorating-ftopict-605188-.html

HTH

I agree with Jan...I have even put under a fan to dry quicker, not my fave but it works. Be sure your fan is very clean and free from dust (ask me how I know) or you could end up tearing off all that work and starting over. mimi