What Causes Growth Of White Film On Penis Glans?

hi i have a white film growing on my glans penis, it is painless, itch-less, and can be easily take off by just gently robing it with soap. I have tried washing it thoroughly, but it keeps returning; and after the white firm been washed out. Also after i masturbated, the white film seems growing faster.I have no other any obvious symptoms, like painful urination, aching testicles, etc. and there is no other abnormal symptoms on my genitals either.I don t have circumcision and my foreskin is normal length.I m worried I may have an sexually transmitted disease or candidiasis.