Wife fell in love with 5th wheel...I have an F150

Yes there are lite 5th wheels your 150 can tow. You will just have to be very careful in choosing one in you weight limits. It ain't gonna be big.

With 2090 lbs of payload. The pin weight of 1290lb leaves you 800lb of payload for you, and DW. However, I'm bettin that is dry, so after you load the 5er. Your pin weight would be more. You need to know the loaded weight, and that is all but impossible to find with out loading it. You just have to figure if you are going to put another 500lbs on the pin.