If you think he's working cash in hand I'd report him to HMRC and I wouldn't give a fuck if he thought it was me. What an nasty *******. You will come out of this stronger and with the love of your boys, but please just make sure you get what you can to support your boys financially.
I know you were just being supportive Blueclass, but I really object to terms like "bleed him dry" - it just feeds the perception that single mum's are money grabbing scumbags, when in fact they are legally entitled to financial support from the father of their children if they separate. Not having a go, I just think it's really important that Luciec knows she is doing the right thing and not being some kind of leech! xx