Stopped Clock Dave is right in that it's a nightmare scenario for Starmer. He's got no choice as the junior partner in multi-layered international relationship but to play nice and say all the diplomatic things, even whilst Trump fires off 'Truths' insulting him as "Low IQ Keir" or whatever. Meanwhile an opposing party leader in the Commons is going to be swanning off to the White House monthly and taking those rictus grin thumbs up pictures Trump poses for. How delightful for the PM to get shown up constantly by our "most important" ally.
But... I'm not actually sure where this leaves the Tories, frankly. They seem completely moribund at the moment, and technically are at their lowest ever parliamentary ebb, with a new leader who can't claim majority support from either her MPs or members. Does Trump act like Reform are the official Opposition? It's not like he's going to remotely understand the UK system or the disparities between the Labour, Conservative or Reform vote/seat shares so when Farage's message is getting amplified from the White House, are they actually going to get overtaken? Probably not, but if they've got a membership that are tuning in to that sort of thing then the howling demands for some sort of deal with Reform might be impossible to ignore.