thug-nasty thirds Share definition Flag Being the third guy to have unprotected sex with a girl. Pretty high risk of STDs If I have to wait and get thug-nasty thirds after Andrew and Roberto again, I'll probably catch an STD. thug-nasty thirds by trojan44 February 3, 2009 0 0 Get merch Get the thug-nasty thirds mug. Buy Now — $32.95 See more merch