semen crust 

When you ejaculate and a crust of semen forms over the hole on the head of the penis

I hate after I cum I gotta wipe off the semen crust nigga

semen crust by Niggalodeon November 16, 2014

crusty semen 

When you nut all over yourself and you let it dry there. After a while it becomes crusty.

I nutted on my hand before and let it dry for a hour or two, it turned into crusty semen.

crusty semen by The Black Plague October 26, 2017