If I was on the bike, I would have slowed down until all traffic behind me cleared out and then passed the group, I do it all the time in my golf cart then I wave to them (not with one finger) as I pass.
Swearing and cursing are not acceptable in any group at any time. I used to cut up a storm but when I got out of my 20's I grew up. I don't think it was intentional but I don't usually get around people who do cus that much, I think in that way most people grow out of their childish ways and finally get out of the gutter.
I think common decency should be the rule of the day.
Stay well, stay polite. :