Am I wrong? I'm just remembering this from Business Law in undergrad. I haven't taken contracts yet. (turned down law school offers to reapply). Not even a 1L yet.
Yeah, I know. No, you're not wrong, but you're not right either.
§16, 2nd Restatement of Contracts:
A person incurs only voidable contractual duties by entering into a transaction if the other party has reason to know that by reason of intoxication
(a) he is unable to understand in a reasonable manner the nature and consequences of the transaction, or
(b) he is unable to act in a reasonable manner in relation to the transaction.
Also, the decision/agreement of sex is not necessarily a contract and does not generally fall under the law of contracts.
In some states, for example, I believe that an attempt to enforce any aspect of an agreement to have sex outside of a marital relationship would be void.