Forum:Shepard - Liara romance question

Hi,

I have a question about this romance. At the guides it says: ""Dr T'Soni?" - Once Liara T'Soni is on board, Shepard can also court her as above after Liara admits looking into Shepard's background. If Shepard has spoken to Liara at all, even platonically, and is already involved with either Kaidan or Ashley, during the next conversation he or she will ask if Shepard is attracted to Liara. Shepard can either express an interest in Liara - which will effectively end the romance path with that squad member - or explain their relationship is only professional."

So what do I have to choose if I want to romance with Liara, not Ashley? That our relationship is only professional? Won't that turn her down?