Based on a person that never got any sex but has since become a general expression.
Nevo meaning never.
Deeds meaning sexual acts.
Thus never acquiring sex (not even blow jaigz)
Guy 1: how was clubs last night, did ya bag any piaar slags?
Guy 2: well...hmmm
Guy 1: what happened, nevo-deedz?
Don't wear that, that shirt = nevo deeds!