Twins with Two Fathers
Twins with two fathers are possible with superfecundation and superfetation. Superfecundation and superfetation and two rare events.
Superfecundation is the word for twins with separate fathers. For this to happen, two things have to happen:
Both of these events can happen on the same day or different days, as sperm can survive for up to 5 days. Multiple ovulations happen in about 1% (or more) of all ovulations, and more often when you take ovulation-inducing medications.
Superfetation happens when a woman gets pregnant again after the implantation of one fetus. For this to happen the pregnant woman must ovulate after she is already pregnant and this egg must be fertilized by another sperm. This can occur weeks or even months after the first egg is fertilized, and the result is that one fetus is more advanced in pregnancy then the other. This is an extermely rare event in humans and has been reported only a few times. Superfetation can happen with the same father or different fathers.