I don't sit in uninvited on other people's wheels and would prefer people did not sit in on mine. If someone does I either ignore it, slow down and let them pass, or pull off and signal them by- and they better keep the pace because I won't sit in but I will be 10' behind them at the same speed I was going before.

Very occasionally and if I'm in a real good mood I'll chat them up and might, might switch off with them.

I really don't like someone on my wheel I don't know. It's such a strange presumption. I will not be pointing out road hazards for them, I will not restrain myself from blowing snot in their face or suddenly come to a screeching halt for any reason I feel like.

So if you sit on strangers' wheels without permission, unannounced and/or uninvited just know that stranger might be me or someone like me- so do not expect to be treated kindly or with much respect.