Is drinking pee of wife sometimes as a sexual activity okey ?

Yes: Urine is usually sterile, and even if it contains a few bacteria these will usually be killed by stomach acid (unless you have neutralized this medically). This should not create a major medical risk.

Oral sex? : If you are referring to having oral sex with your wife meaning you place your mouth on her genitals to stimulate sexual arrousal then yes this is ok. If you are referring to actually drinking her urine then this is not advised.

Depends on how much: Whether pee-drinking causes any problems depends on how much pee and how often. Pee is normally clean and sterile (otherwise, one would have a bladder infection). However, pee is also how we rid our bodies of certain chemical waste products. That means pee-drinking should not be a big part of life's activities.