Any large rock. A sex rock is often found around a house in the landscaping. A sex rock can be any shape but must be large enough to have intercourse on.
by patsy ulso December 24, 2011
Elusive rocks found on the shores of lake Huron. Legend has it if you find a rock with the word sex etched into you can exchange the rock to anyone you wish for sexual favors.
by Crispy boy June 28, 2018