Got new plate, don't know much about her. Sex is great, though I want to do some stuff with her but I need to know if she's seeing somebody else first or I'm not doing that ( yes, I'm still gonna use a condom ).

Now: I don't care if she's seeing someone, I just would not do that sex stuff with her then. And second I don't want to delve into my sexual history or who I'm seeing.

Is this realistic in any way or am I shooting myself in the foot by even bringing it up? what's the best time? After sex?