Never try to solder several wires just barely twisted together in your underwear.
The wires will absolutely come untwisted and accurately catapult hot liquid solder into your lap and it will burn through your skiivies in 4 milliseconds then on to the very end of the most sensitive appendage on your body.
I have done this just once.
Then try explaining the red marks to GF.
1996 Gas Gas JTR270, 2001 Ducati ST4
1977 Honda 750F2, 1970 Honda QA50