In Dutch we have the word voorschieten. In English it translates — according to Google Translate — to "advance, lend, disburse". The Dutch word voorschieten is used in an informal setting between friends where you pay for that friend's dinner or drinks and expect to be paid back later.
Do you say in English "Mary loaned John money for the drinks"? or "Mary advanced money for the dinner"? or do you use another expression? Loaning sounds a bit heavy to me. It's like "A loan for a car".
A friend from New Zealand came up with "Mary spotted John money for the lunch", but I wonder if it's understood in the US.
Best Answer
In first-person conversation, I would generally say something like "I'll cover this one, you can get the next" or "I've got this, you can owe me." Or, going the other way, "If you could take this, I'll pick up the next one."
As @Jim mentions in a comment, "fronting" is a good term too. "Bob fronted Mary a twenty so she could pick up the new release while it was on sale" would imply that Bob expects that $20 to be repaid.