I didn't romance Morrigan, but I did knock her up because my Cousland and the other Warden's lives were on the line, but the decision brought me pause and I really went back and forth over it before I finally went ahead.
It was basically a huge roleplaying moment as in what made sense in-character. There's all the factors like how he was usually someone who tried to do the right thing or what that wouldn't harm the undeserving and his devoted romance with Leliana and the feelings of betrayal (would things be better if you could admit the situation to your love interest rather than keeping it a dirty little secret? I can't decide), and to have a bastard child he has no intention of being a father to with another woman through a dark ritual which might cause who knows what to happen to it. And of course even if its unharmed there's the fact this child will have the archdemon's supposedly purified soul and he would be turning it over to Morrigan to go off and do who knows what with it. Though at the same time he had become close friends with Morrigan (Its touching how she seems so confused by platonic friendship with a man and all that). Flemeth had been his "most powerful foe slain" since level 8 and while its possible Morrigan could become a threat and it had all been a ruse... it seemed after all this time he could trust her enough not to do anything that would require killing her later.
Sorry to blog like that but I just got to the part this very hour in Awakening, with the same character, where Oghren's second wife comes in all angry at him for abandoning her and their child... it makes you think... and then your striking image brought it all out. Wonder what it'll be like when I get through the expansions to Witchhunt