How to translate "suit yourself"? I'm curious as to how it translates to Latin. In certain contexts, it can come off as rude or sarcastic, even though, it's used in formal conversations and is not intended to be offensive.
I would translate this with a common Plautine injunction:
Age ut lubet!
Ut lubet! / Ut libet!
Here are some examples in context:
Immo age, út lubet, bíbe, es, disperde rem. (Plautus, Casina 247)
Go ahead, suit yourself! Drink, eat, waste your money!
Med. ...ibi meo arbitratu potero curare hominem.
Sen. Age ut lubet. (Plautus, Menaechmi 949)
Med.: In my opinion I can cure the man there.
Sen: Suit yourself.
More polite, with sis (= si vis):
Ant. Eamus, mea germana.
Ad. Age sis, ut lubet. (Plautus, Poenulus 329)
Ant. Let's go, sister.
Ad.: Sure, as you wish!
This lubet is colloquial and less common in later works, though Cicero does use ut lubet once. A more standard way of saying this would be ut libet. For example:
nam mihi in mentem non venerat. 'non credo' inquis. ut libet; sed plane gaudeo, quoniam τὸ νεμεσᾶν interest τοῦ φθονεῖν. (Cicero, Epistulae ad Atticum 5.19.1)
For it had not even occurred to me. "I don't believe you," you say. Suit yourself. But I am quite glad, for resentment is not the same as ill-will.
Ut lubet can easily be inserted with another verb in the imperative, e.g. perge ut lubet. This can be translation: go right ahead, ironically or not.
I'm not familiar with an actual idiom for this purpose, but let me propose a phrase the Romans would likely find natural. Here is a phrase with similar idea:
neque me Iuppiter neque di omnes id prohibebunt, si volent,
quin sic faciam ut constitui.
(Plautus, Amphitruo, 1051–1052)
In addition, the phrase sic facito is ubiquitous in Cato's De agri cultura. These two can be adapted to say "suit yourself":
Sic facito, ut constituisti!
Do as you have decided!
This is certainly not the only way to express the idea. This just happens to be a structure for which I find support in extant literature. The future imperative is not necessary; the present imperative fac is also fine, but for some reason I like it better with the future one.
The phrase Sic facito, ut constituisti! is polite. But like anything else, it can be used sarcastically or in a negative tone. I would consider the tone to be fairly close to that of the English idiom.