I tried this with a bigger group,but the male nor will the female mate with another. Imagine if humans were the same . It may be possible for a danio to mate with another,but again from research and experience it's unlikely.
LOL, these guys are so far down on the food chain that pairing for "life" might be a couple of days until one of them gets eaten. I breed Giant Danios and I've never noticed any permanent pairing. I guess mine didn't get the memo.