How about something like 'Do you want to get some coffee after class today?' That sounds about right.

[Derek hasn't talked a lot about his college days to Kenta... but from those words, it's easy enough to understand. Not that Kenta would ever judge anyone for that, especially not a 19-year-old college student.]

Derek, we're in college. People party and sleep around. It's something that happens. Besides, she knows and she's still talking to you and laughing with you, so I don't think it's bothering her that much.