The world hates half-wheelers.
You chose to ride this ride. Slow down. If you can't control it then apologize to everyone on the ride and pick a different one.
I despise when people choose to come on slower rides then constantly half-wheel it. It's not that hard to go slower, or to wait. The easy ones are stopping. When you come to a crossroad take the time to fully stop. Then don't accelerate out of it like you're sprinting out of a corner in a crit. I find that is how a lot of riders will gap the ride without intending to.