Source (Pixiv)

Translation:

Panel 1:

Espeon: Eevee today is a special day!

Umbreon: It's 24th day

2:

Espeon: It's called Christmas Eve

Eevee: Christmas ... Vee

3:

Umbreon: It's Christmas Eve not 'Vee'

Eevee: Christmas... Eevee!

4:

Since today our family has also started calling it "Christtmaseevee"

Flareon/Jolteon: you too?

Umbreon/Espeon: Yes.