I’d wait until next semester, then ask him for coffee with the excuse to talk about being a grad student. Even in very different subjects, will you have TA responsibilities? You could talk about TA tips, how to live on a grad school stipend, etc. I had a “yuge” crush on a TA in college (Tim who did his undergrad at Amherst and was a geology TA at Michigan, in case he is reading 
). I couldn’t figure out how to bridge the gap, although I got a GREAT grade because I spent a lot of time in the lab!
@traveller2013, seriously. Your thread has already shown you don’t understand consent, school policies on sexual assault, or even sexual assault itself. None of which are particularly likely here.
Another point to add: the TA might be afraid of having a relationship with a student and might feel weird about it if it happens too soon after the class ends. I will be a TA in the fall, and practically all my professors have been telling me “when you’re a TA, DON’T date your students, DON’T party with them; don’t do anything with them!!”
So, it might be better if you wait until the fall when you’re both graduate students because this guy might have had the fear of God pounded into him!!
Tell him you’ll do ANYTHING for an A.