Our TT is 10 years older, but we do have cone washers on all the lines that connect to faucets. I did have to buy a few from our local RV dealer as none of the ones at the hardware store were close enough to seal correctly.
I replaced both sink faucets with better ones, and if I wasn't very careful re-attaching the lines, the cone seals would deform just enough to drip. I now carry a pair of spares.
If you're going to "regret it in the morning", sleep until noon.
2012 Jay Flight 19RD
2016 Ford F150 XLT 2X4 SC 3.5L Eco Max Tow
2010 Tundra TRD DBL Cab (Traded)
2 new fluffy Corgis, Bayley and Stanley