Got myself into a minor pickle this morning - had been filtering on the right in slow/standstill traffic and then, once traffic was slightly moving again I wanted to move back over to the left. Found a gap in the cars and slotted in, no worries, but wanted to continue into the left hand cycle lane. Did a shoulder check and saw a cyclist coming at speed so let him go and went to follow him when he passed. The cyclist behind him though, rather than easing off slightly, decided to put the hammer down and stop me moving over - I ended up in no mans land between the cycle lane and secondary. Which was vaguely ok but not brilliant really - I'd usually slow down in these cases and slot in behind the speedy cyclist but I had no room to manoeuver with traffic following me.... We started to go over the junction like this and I really needed to turn left but he kept trying for the undertake! Was very annoying - just ease off dude, it'll all be fine! Managed through many shoulder checks and a long left turn signal to get it through his head that undertaking is not helpful. It was probably my fault in the first place for assuming that he'd let me in, but once the mistake was made he could have helped me out, I slow down for other cyclists all the time...