Your character needs to be in the aroused state when you talk to them in their room. Well, Bunaby and Yikshi technically have a dreamscape in their contract scene!
Oh, don't worry about it! yeah, for the valentines, Sanma, Yikshi and Bunaby don't have one. Ah, I thought I got every bug in Dren's and Fang's dreamscape. I'll be fixing that as soon as possible!