Valery Markus (a very well connected Sergeant in the Ukrainian AF - and whom I think you might have mentioned) has a YouTube channel.

In one of his videos - the one about the 47th brigade's attack on Russian defenses, there's an English closed caption available (looks to be web interface only, select 'CC' then 'English'). In the translation he and his guys seem to refer to RF forces as "suckers". There's a Cyrillic subtitle embedded in the video - and "л*дap" seems to be what it's translating. I would guess, just from the asterisk that that word is something offensive, but I’ve no Russian or Ukrainian — although I now know that Ukranian ‘yes’ is ‘tak’ — not ‘da’.