Identifying two chinchillas

[RXM]

Hi! We just picked up a pair of related chinchillas (3mo) and would like to confirm their sexes!
The buyer thought they were both female, but upon looking, we believe they're different - given size differences, one trying to mount, and space differences in genitals.

Here is the first one:


And here is the second one:


Would appreciate help in this. Thanks!

 

[Spoof]

The first one is a male, the second one is a female. They have not likely bred yet at this age but will need to be separated by at least 8" permanently. They can and do breed through bars.

 

[Amethyst]

I agree you have a male and a female. It can often be easier to see if you take a look from the other way, front feet on a surface and lift the tail up, if there is a gap between the cone and anus it's a boy (or if there is a gap it's a chap), no gap it's a girl.