Approached the lights in the filter lane to turn left, car just coming up behind. I take the turn and shoulder check and signal to pull into the right lane almost immediately, car is behind, shoulder check again and he's overtaking me. Follow him down the lane, lights on red, so I pass him on the left and into the green box, lights change, I set off followed by horn beeping. I ride primary as I need to cross to the lane for another right turn into lidl carpark, I don't think he was happy about it, he was going shopping too. As I'm locking up the bike he approaches me. "clearly you have something to say to me" I say, but he claims it wasn't him beeping the horn. Perhaps I should've apologised? I didn't "When a cyclist signals they are going to pull out it isn't a good idea to go ahead and overtake them anyway" I tell him. I wasn't using my inside voice -but we were outside. "You need to learn your signals" he tells me "You were wobbling all over the place (I did wobble a little when I shoulder checked) and sticking your arm out" "Sticking my arm out is signalling!" At which point he lost interest in the conversation and wandered off shaking his head and muttering. He was obviously communicating his irritation with all other pensioners in the vicinity because a little old lady then shoved me out of the way in the queue and the old man behind me rammed me with his trolley. I shall think twice before arguing with pensioners in future!!