well, trust me, don't even think about the negatives. There are some (mainly just stupid nervousness or embarrassment), but they do NOT outweigh the positives. Not by a long shot. So never let the negative reasons be a reason why to not go for anything like that on a whim.
If you have to I would be just mildly drunk to calm the nerves as well as having a visible "excuse" so to speak for not performing as well.