Sex0r is an noun for sexual activity, meaning the range of sexual occurances that can be achieved in a l33t environment.
n00b_h4x0r: omg imma get s3x0r =O!
c001_d00d: Ur t3h g3!g|-|, u are just going to go on teh pr0m omg
n00b_h4x0r: hahhaa, n00b i r got g/f (H)
imma get r33l s3x0r
c001_d00d: wtf, />|-|46