I have had this discolouration for weeks(5). last sexual in January but only dry humped naked. we were both virgins.
sti test (Hiv, syphillis , Chlamidya & gohnerrea) in march all came out negative.
this discoloration is very flat to my shaft skin and its not itchy or burny.
Not being itchy or burny is a good thing it shows there are no signs of STIs and no infection. It looks like a skin rash to me.