This is a statement made to indicate a situation a person doesn't want to just come out and say they enjoyed.

Something unexpected or unusual that the person in question wants to share with the group and when questioned on it; rather than give a straight answer, they say "well let's just say i wasn't mad about it".
Jeff: So last night maren came over and wanted to all of the sudden hook up so we made out for a while and she went home.

Beck: so how was it, that was a nice little nugget for the night?

Jeff: Let's just say I wasn't mad about it
by Randoni April 6, 2009
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