You put a female with male type X and he fertilizes some eggs, then you put male type y and he also fertelizes some eggs. Will you get eggs that are type X and Y?
You can, however gecko females retain sperm so you would have no idea what male fertilized the second set of eggs untill they hatched, however if you left it long enough into the breeding season and the female was not bred till later and you put her with male y it would be more likely to be male y's hatchlings as usually the newest deposit of sperm fertilizes the eggs.
However this is not a guarentee.
Many females will retain sperm for the entire season. If you rebreed her with a different male and it is successful, you'll still have a very hard time knowing which babies are from which male. It's a better idea to stick with one male to a female per season.