The D word

So my trainer has expessed an interest in me which is weird because 1) i'm a fat geek and 2) he's 10 years older than me.

Now, i'd like to ask him out but for a fitness nut, you can't exactly ask them for a drink. Or coffee.

I've been pondering the nest option of these two:
Wanna go dutch on a wheatgrass shot?
Or
Wanna join me for a protein shake somewhere?

It just doesn't work as well as Can i buy you a pint?

Ugh! Dating is hard....