What will likely effect be if the bulbourethral gland in male fails to perform its function

The effect that will occur if the bulbourethral gland in male fails to perform its function is that the sperm will not survive the acidic conditions in the vagina. 
The bulbourethral or the Cowper's gland produces watery, slightly mucoid fluid that neutralizes any acidity in the urethra that is left by the urine that passed through it, and therefore sperms are not harmed by this acidity. Additionally, the fluid helps in neutralizing the acidity in the vagina.