From my studies, I would postulate that conjoined twins probably end up having less sex than average people, and that is not only because sex partners are harder to find when you're conjoined.
Conjoined twins simply may not need sex-romance partners as much as the rest of us do.
Based on what we know about the significant variability of one conjoined twin to feel a body part (e.g., an arm) that putatively "belongs" to the other twin, it's hard to guess how any conjoinment will turn out in practice.
Chang and Eng were joined by just a bit of liver and some skin.
One April day in 1843, Chang married Adelaide Yates, while brother Eng married sister Sallie Yates.
Yes, this was considered better than leaving the children alone.
So, I suppose I should get to what the people really want to know: what do conjoined twins feel when they have sex?
When filmmaker Ellen Weissbrod set out to do an A&E Channel program about Lori and Reba Schappell, who are conjoined at the face, Weissbrod showed raw footage of the twins to New Yorkers on the street, without explanation, to gauge their reactions.