Yes it's sometimes possible for a woman to become pregnant by two different men or guys and have twins that have two separate fathers.
When that happens and a woman gets pregnant by two different guys it's called heteropaternal superfecundation.
The heteropaternal superfecundation happens when two of a woman's eggs are fertilized by the sperm of two different men.
So yes it's possible that if a woman has sex with two different men and they both fertilize the woman's eggs then they could give birth and be pregnant with 2 babies that are known as twins but with different fathers.