Sperm is the male reproductive cell and egg or ovum is the female reproductive cell.
Usually, two sperm cannot fertilize the same egg. The reason behind this is that when one sperm comes in contact with zona pellucida then some changes occur in the membrane which prevents the further entry of sperms which is called polyspermy.
If two sperm fertilize one egg which is a very rare occurrence in 1% of the case the embryo can’t survive.