In OTL, the British actively sought an alliance with Russia after the Seven Years War. Russia was interested, but negotiations foundered on the fact that Russia wanted Britain to provide protection against an Ottoman attack as part of the agreement. Britain wasn't hardline against this, but had enough worries it bogged down negotiations, and Russia eventually got bored.
But what if Britain was more worried about its international isolation and reluctantly agreed to such terms? Let's imagine that the Russian alliance put off France from getting involved in the ARW, so the Revolution is crushed and the French revolution is delayed. We then get an alternative Russo-Turkish war in the late 1780s, but with Britain on Russia's side rather than Austria.
I assume this would be a bit of a curbstomp of the Ottomans, faced with the Russian army and the British navy. Could the British succeed in attacking Constantinople from the sea and occupying the place? What would the peace deal look like? I imagine something like the Crimean Khanate to Russia, Crete and Cyprus to Britain, Morea as an independent British-aligned Greece, and Constantinople made a Anglo-Russian condominium.
Thoughts?