My ex is at it again......
Background, I'm a single parent to a 22m old DD, have been so since she was 4m old.
By some small miracle I've found a new partner (something that I never thought would happen!) and we are getting on very well, albeit taking things very slowly - our 'dates' so far have been daytime, child-friendly things with DD there. I'm not subjecting my DD to watching us doing anything more physical than holding hands.
Ex-H, however, has come to the decision that, as I am finding time to see another person then I am definately neglecting DD as I should 'be focussing on her'...... and it is 'unfair and practically abuse' to bring another person into her life.
In case he is concerned that DD will 'have another dad' I've reassured him that he (ex) is her father and I'm not looking to replace him in that role, to which he replied that should he start a new relationship, he would be encouraging DD to call his new partner 'mummy' when DD was with them on visits etc, as this would be 'less complicated and less confusing, so better for DD. And she'd probably be a better mum anyway'......... 
I've never dated as a single parent before, so this is un-trodden ground for me, and I know ex can say some ridiculous things, but I'm seeking reassurance - by starting a new relationship that does not make me a neglectful parent - does it?