Semen or any other ejaculatory fluid which has been excreted from the body and hardened on any surface.
The other day my Mom was washing my jeans and confronted me about the lust crust on the left pant leg.

When that bitch did the walk of shame I caught a glimpse of some lust crust on her inner thigh.

When that skank rolled outta my bed I noticed her pubes were decorated with my lust crust.
by oh jaspy August 13, 2009
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