EvilDIL you hit a chord when you said they think their other DIL is lazy. Your MIL doesn't think you or sister in law do enough for their precious boy. Before we were married, DH's mum said "no girl will be good enough for my boy" and for the first couple of years she'd say "hello love, you're looking a bit peaky, are you eating enough? Would you like some apple pie?" (he was, and still is, a bit of a chubster!). However, she mellowed over time and we loved each other.
They are very old fashioned in thinking that a woman's place is in the home and the husband rules supreme. It's unlikely they will change their views overnight but if you give it time, they will see that your husband is, in fact, being loved and 'thriving'.
Just be pleasant when they are around (even if it irks you inside) and I'm sure they'll eventually realise that things have changed and you and DH are happy doing what works for you.
Which British song sums up the 1960s for you?


