ceatine does affect sperm negatively. see here:
Sexual Side Effects of Creatine
By Ann Olson, eHow Contributor
Sexual side effects are commonly reported in men who take creatine to build muscle. Several reports--and numerous complaints from men--confirm the debilitating effects of creatine. Here are the most common sexual side effects reported with use of creatine.
Decreased Libido
An overdose of creatine may caused decreased libido. It is unclear why this occurs, but some scientists believe it is because the body cannot digest creatine at higher amounts, leading to sexual side effects.
Erectile Dysfunction
Another sexual side effect of creatine is erectile dysfunction, which inhibits a man's ability to have an erection. Many users report this side effect after cycling off creatine.
Inability to Orgasm
Many creatine users report inorgasmia, or an inability to reach orgasm.
Inability to Ejaculate
Many men are unable to ejaculate as a result of taking creatine. It is a temporary but severe side effect that may decrease male fertility.
Decreased Fertility
All of creatine's side effects cause another sexual side effect, decreased fertility. This is called subfertility, which temporarily decreases ejaculate volume, ability to maintain an erection, and sperm quality.
Read more: Sexual Side Effects of Creatine | eHow.com
http://www.ehow.com/facts_4886419_se...#ixzz1Mkd4WmDT
This is very scary