Before I was a single parent I was still the breadwinner, making about 2x that of H and carrying the insurance. I suppose I was "lucky" in that aspect that when H left money was a huge issue for me, I could still support myself and DS.
Fiance works but I make more than 1 1/2 times what he does and my benefits are great, his are practically non-existant. He has health insurance which they pay all but 10% of (and it has very high co-pays and deductibles) and that's it. No 401k,nothing.