Loki is nowhere near as concerned about Peter's nutritional intake as Steve is. It's just not the kind of thing he thinks about; he is not considerate. But he can be generous when he's in a good mood and feeling flashy, and a milkshake isn't much of a splurge.

There will be extra whipped cream. They have already established that you can't sit at the Loki table unless you have extra whipped cream on your shake.

"I suppose I can't criticize that. I never tried until tonight, although I'd heard of it before."

"Yes, you put the stem in your mouth and tie the knot before you take it back out." Peter, if you get it on the first try, he's going to be annoyed.