This is very obviously not a double standard, as the first one directly affects Europeans in a way which the second one does not.
Imagine, Germany bans Russian oil, does it make you a happy if they buy oil from Saudi? For me its same, both sides are killing innocent people, why make a switch then?
No matter how evil the Saudis are, their bullshit does not affect me in the same way that Russian actions do.
That's the reason why Ukraine war happened. We don't care, unless it is happening in our neighborhood! Now it is too late.
when is it simply hypocrisy?
hard questions.
War in Ukraine directly affects European security and pushes millions of refugees into Europe. The Yemeni conflict obviously does not directly affect Europeans.