Question

Can 2 sperm fertilize the same egg?

Answer 1

Generally, two sperms do not fertilize the same egg. When one sperm comes in contact with the zona pellucida layer, there occur changes in the membrane, which prevent further entry of sperms. Two sperm fertilizing the same is very rare and occurs in very rare cases and embryos usually do not survive.

Complete answer:
Yes, 2 sperm can fertilize the same egg.
Fertilization is the process of fusion of haploid gametes, egg, and sperm, to result in the diploid zygote. This starts with ejaculation during intercourse, followed by ovulation simultaneously around that time and ends with fertilization.
After fertilization of sperm in the ovum, the cortical granules within the oocyte fuse with the plasma membrane of the cell, and are expelled into the zona pellucida, causing the surface to become hard and impassable. The process is termed the cortical reaction and is responsible for ensuring that only one single sperm cell can enter and fertilize the egg.
Non-identical, or dizygotic, twins occur when two separate eggs are fertilized, each by different sperm, and develop in the womb at the same time. If one egg is fertilized by two sperm, that results in 3 sets of chromosomes, rather than the basic 2 sets - one from the mother and two from the father.
"It’s likely the mother's egg was fertilized concurrently by two of the father's sperm before dividing,"

Note:
Identical twins result when cells from a single egg fertilized by a single sperm divide into two, so identical twins are the same gender and share identical DNA. Fraternal twins occur when each twin develops from a separate egg and the egg is fertilized by its own sperm.