Assuming both your loans are low money down and you have mid-trim or higher versions of each ($100k+), you realize that once you finish paying off your Model S and Model X, you can then "afford" the monthly payment of a new Roadster? #mentalgymnastics
All depends on the insurance costs for a New Roadster... the Classic Roadster is pretty affordable to insure.
I'll give you a buzz next time we're in Vacaville. We can "randomly" strike up a conversation and then you can drop this bug in my wife's ear.