Re: Jennifer Lawrence/Mystique. Introducing this sexy and talented actress.
I wouldn't think it would be shown, but rather more exposition. Like, we would find out when Charles asks her who the father is, then Raven starts to cry, Xavier reads her mind, he too gets very upset. Hank asks, but gets no answer; not until he (and we) see the baby which has Azazel's features. They never even have to say it; it'll be heavily implied. And then when Azazel gets confronted - maybe by Magneto - he, Azazel, will just laugh, showing no remorse.
This post was premedicated.