You only have the obligation to pay spousal support ("alimony") when you are actually married. While a number of court decisions have allowed claims for support between unmarried people who have lived together ("cohabitants"), these claims are different from the claim for alimony.
An alimony award is generally paid in "periodic (regular) installments, usually monthly.
When Must Alimony Be Paid?
Both spouses in a marriage are expected to work for at least a substantial portion of their marriage. When a marriage ends, there should be no expectation from either spouse for lifetime support.
In a marriage of relatively brief duration (under five years), the courts most often assume that:
Each party has kept the same ability to support themselves from prior to the marriage.