My DC don't like their dad!

[Roisin80]

I have 3 dc, expecting number 4 in a few months. My dc range from 4 to 8. Recently the two eldest have started to pass comment on my husband, their father, saying he is so grumpy, he's always cross. To be honest, he is pretty grumpy, he doesn't mean to be but he's just very controlled emotionally, doesn't get very high or low. I have mentioned it to him and said what the dc have said but it doesn't make any real difference. I'm not sure what to do as in a way it puts an extra strain on me because they don't really want to spend time with him.