Sometimes during she just isnt turned on? normal?

Ok we've been together for almost 9 yrs. We recently got back together 2 months ago after a 8 month break up. We've been having more then before we broke up. Before it was once ever week or 2 now its 4 times a week. We live in 2 different places just till I sell house then were moving back in. And everytime we have we get each other off. Well yest we went to a movie and dinner wit her dad. And the whole time she kept sayn she was turned on and wanted me so bad, I was willn to go anywhere lol but she said no cuz of her dad being present. So she said later after movie. So we go to her house and start messin around. I go down on her and she does same to me. And when I was just about to put it in her she tells me..I'm not turned on..so I'm like well wtf!! So we try to have and she's just not turned on or gettn off..does this happen to other people? Was it just an off nite for us? Lol jw