What do you think is my favorite book?
Fishing? That's just my cup of tea.
He seems to have a liking for my children.
And I have to tell you, I'm passionate about numbers.
I was quite captivated by his appearance.
He likes pop; he doesn't care for classical music.
It is not really my thing.
One does not typically have a "penchant" for a person. You have a penchant for doing something or for an activity. He could have a penchant, for example, for talking with your children. He could have a penchant for "being" with your children, since "being" is an activity.
"Prepossessed" is not wrong, but do you want to use such a strong word? It means captivated to such an extent that it excludes other thoughts or feelings.