Son super embarrassed about voice cracks

My 14 year old’s voice is changing. He’s sooo embarrassed about it. I will admit objectively speaking it seems pretty bad compared to most people I know.

I told him I thought it was cute. Wrong answer. Realized it as soon as it came out of my mouth. He says “this isn’t funny” and then literally starts crying.

I say I’m so sorry I didn’t mean it like that. Then I just said he’s becoming a man and I know it’s tough but the end result will be a nice big strong deep voice and it will be worth it. He tells me to just stop talking about it.

His 10 year old sister mentioned it one day, not really trying to be mean or anything but I know it embarrassed him and he got mad at her. I told her not to mention it do him.

He’s so frustrated and uncomfortable about it. To the point I feel like he’s talking less because of it. Is there anything I can do to help? Any experience here?