Can’t stop thinking about ...

When I was pregnant with my first son, I had a sex dream with my SIL. This lead to some fantasizing but it eventually went away. It completely confused me because I never had been attracted to females before. Now I’m pregnant with my second son and I can’t stop fantasizing about sucking on nipples and licking pussy.

It’s so strange to me and it’s weirding me out. Is it because of the extra testosterone in my body?