Male-female pairs are fine...I keep a trio, 1.2 ... they live in colonies in the wild, so having a male essentially run a territory with females isn't a foreign concept for them....
2 males is fight for territory though...the difference in the wild is that the loser can run off...in captivity, not so much.
That's a little strange that she's got a male but the eggs are infertile. Are these her first couple of clutches? Are these slugs or infertile eggs? Slugs are the small dark dead looking eggs, while infertile eggs appear normal but go bad during incubation and never hatch...
Its not abnormal for a female's first clutch to be infertile, but throwing slugs over and over again...that's a little odd.
What kind of vitamin/mineral supplements are you using and how often?