The research that's been done on STIs and HIV amongst adult TIFs indicate that a good number of adult TIFs have penetrative penile-anal sex with men in which the TIFs are the receptive parties (bottoms). But this research was done before the outbreak of ROGD amongst teens and young adults.

Whether most adult TIFs can be characterized as straight and bi rather than lesbians is hard to say. For all the talk about "being true to their authentic selves," the impression I get is that a lot of TIFs actually have no idea who they really are and what their true sexual orientation is. I don't say that as criticism or condemnation of them. It just seems that many of the people caught up in the trans craze suffered abuse, trauma and dissociation early in life, and unfortunately are still reacting to how others have treated them in the past rather than acting according to their own inner desires and inclinations.