Monkey sperm cannot fertilize a human egg.
Humans and monkeys are actually different species and have their own distinct genetic material.
Human sperm is restricted to the Hominoidea and human sperm will also not attach to the zona of non hominoid primate oocytes.
Being able to fertilize another species eggs is determined by the amount of time which has passed since the last common ancestor of the 2 species.
The last common ancestor of the human species and chimpanzee species is estimated to have lived 13 million years ago.
However chimpanzees and humans may have continued to have sex and also produce offspring until as recently as 4 million years ago.
Although both humans and monkeys share some similarities, humans and monkeys are different species that have distinct genetic material.
The differences in the humans and monkeys DNA make it impossible for monkey sperm to fertilize a human egg and create a viable offspring.