Dragon Age: Origins Message Board  

just so people know, Morrigan will continue to sleep with you even if her approval is 100 she only stops sleeping with you when... Spoiler:

If you use the console command to get her approval up, then make the right dialogue choices and give her the black Grimour I was able to get her to sleep with my character @ the first camp and in less then 5 minutes. You just have to talk to her right. She is cake compared to Leliana, though I managed to bed her, Zevran and Alistair in one shot @ camp with my female character, playing with the approval rating and plot gifts .