Here's a good rule of thumb: If you don't want them to mate, they'll be doing it all day long. If you want them to, the male will be disinterested. Just kidding, but keeping them together is a gamble.

There are things you can do to improve their odds of mating, but they are individuals... some males are good breeders, others aren't. I wish I could offer more definitive advise, but it's definitely a risk... particularily if they're both captive born. There are no guarantees when you're keeping a male and female together.