Maybe I'm mistaken.

[lilwanderer]

Are you sure the chicks are Ermine? Im not familiar with the mutation, but less common mutations are often recessive. If they are recessive both parents have to have the gene. In order for my chicks to be mottled (looks like what you call Ermine) both the hen and the rooster need to have the gene.
If it is recessive your boy has two copies and all his offspring will carry one copy. The next generation would have more chicks with the color pattern again.

they are

 

[lilwanderer]

If the white stripe is over a black spot, then yes. I've seen barring on a Cornish Cross that had a spot of leakage.
Pay close to any spots that appear in their feathers, and hopefully you will get your answer.

Safe to say this is a boy then-? those two prominent black feathers appear to be barred (the stripes) right?
I think the other one could be too but it's not as obvious so I'll wait it out.

 

[NatJ]

Safe to say this is a boy then-? those two prominent black feathers appear to be barred (the stripes) right?

I think the same thing you do about the chick in that picture. It looks like barring across the black feathers, which would mean the chick is male.

 

[lilwanderer]

I think the same thing you do about the chick in that picture. It looks like barring across the black feathers, which would mean the chick is male.

I thought so.
I've got more hatching, these were tests to see if eggs were fertilized and they were the most recent ones.
The others I've set have all consistently been fertile so I'll definitely have more!
Once I get one with an obvious white spit on the head it'll be easier.

 

[lilwanderer]

I think the same thing you do about the chick in that picture. It looks like barring across the black feathers, which would mean the chick is male.

More pictures of the mama i found when she was younger- You can see the barring in her neck in these I believe. (If I know what I'm looking at it, I believe I do lol.)

And I finally found a picture of her sexlinked son from a previous hatch with a different father. Very clear white spot!