More of a headcanon with regard to Ten

Officially, Time Lords are fairly immune to the affects of alcohol, and can only get drunk if they want to. In addition, they can very easily snap themselves out of it.

The Doctor, in his Tenth incarnation, is both a silly drunk and a sad drunk, depending on the circumstances and the level of drunk he allows himself to be. There is no in between.

Imagine Zepheera stumbling upon her Time Lord after he’s had way more than a few. He’s either singing loudly and off-key and laughing at/with inanimate objects, or he’s curled up in a ball of despair shaking with silent sobs. Either way, the borrower will eventually get noticed and he’ll suddenly become very still, all effects of inebriation leaving him at once.

Zepheera will comfort him without even questioning what drove him to get so drunk in the first place, especially in the latter situation. She’ll remind him that what’s done is in the past, and he’s not alone anymore.