This paper presents the first attempts by economists to estimate an equation of the demand curve for sexual relationship partner attributes. The focus is on the age of partner sought as the item demanded. A sample of newspaper ‘personal ads' is used to construct the demand curve. The estimates show clear evidence of age trade offs in partner search which vary by gender. There is evidence that financially constrained men will trade down in terms of market desirability, i.e., up in partner age, but also that women will offer to buy younger partners with financial signalling.