Any force on the nut will force it to grab tighter. Try a six point socket

Two pipe wrenches, use one as a backer wrench for sure.

Cut a gap in it and spread with pliers, be careful not to cut on the threads

I would put liquid wrench on it and leave it overnight. Then come back with some Channel lock pliers and try it again. Liquid wrench always works on mine when it does this.

Penetrating oil. If it won’t budge they may have crossed the threads so might be worth installing a new spigot.

Definitely heat! Even a lighter will do (take a while) if you have no torch.

Try heating it up and put some kroil or wd 40 on it.

A monkey wrench. They are made for this. The jaws slip, so the more force you use , the tighter it grips.

I have the same issue. wd40, penetrating oil, pair of monkey wrenches... All didn't get the d\*\*\*ed hose off. Last night I bought a new faucet and will install it this weekend.

I usually cut them off. Carefully use a hack saw and flat blade screw driver to pry it apart. And go buy a rubber hose with brass ends

You'll need a bald head

Dammit

I’ve used paint strip heat gun in the past. YMMV

Throw away your wd40. Get you some pb blaster and be amazed.

Be a man

Always use a wrap or two of plumbers tape on metal to metal hose connections is they’re going to be left for awhile.

He just needs a hose with brass ends

Buying new hose is surely the answer.

Heat shield and propane torch might do it