"Potions" (DMG, p. 139) says:
Drinking a potion or administering a potion to another character requires an action.
While I accept that a player can administer a potion (particularly healing) to an unconscious character, it suddenly came up last week that someone wanted to feed a healing potion to the fighter while he was conscious and in combat (with both hands holding weapon/shield).
Is this allowed?
My sense of "administer" is that it's something you to do a creature that is still. You have to grapple a patient before administering a syringe, for example.
It also seems unrealistic to have the wizard slipping in amidst melee combat to pour something down a fighter's throat while they are dodging.
But before I make assumptions that everyone agrees with what I see as "obvious", I figured I should check and make sure I'm not missing something (it's happened before!).
To address from a comment, I feel this is different from trying to force an opponent to drink a potion (of poison, normally). An ally is actively trying to stay still and be fed the potion, while an enemy is actively trying to avoid drinking the potion.