its not true
a cirumcised male (if circumcised fairly early in life) has his foreskin cut off
underneath the foreskin is your head iof the penis (referred to a the penis glans)....this is not skin, but something called mucous membrane (like a crappy version of skin basically,)
its thinner and more sensitive, and also get damaged more easily, so there are usually lots of little microscopic cuts in it that HIV can get through
now circumscision early in life basically exposed this mucous membrane to the outside world, and you penis head will eventually
keratinise or toughen/thicken (skin is keratinised)....as a result your head or glans becomes much tougher (like skin) and more resilient to viruses like HIV (skin is a fairly good barrier against HIV but not infallible, if its cut HIV can still get through and its not been proved as 100% just low risk etc). Also the hole where your urine comes out your pecker (the urethra) is mucous membrane and HIV can still get in through there
SO....what does this all mean.....
as a circumcised man has less mucous membrane on his penis, there are less ways for HIV to get in and as a result he is at a LOWER risk than a uncircumcised man for contracting HIV.
HOWEVER HIV can still enter his body through his urethra and any cuts on his penis in general.....so the
ONLY way to provide decent protection is a good quality latex condom, one of the few things proven to stop HIV
if your friends do this they are still at risk
