You should have agreed before hand what was going to happen, but if I were riding with friends I would expect that we kept pace with the slowest member - whether that was me or someone else.

When uneven terrain comes into it, I would expect that those who climb faster wait just over the crest of each hill for the slower climbers to get there/catch their breath.

On flat terrain, I would expect the faster members of the group explain about drafting to the slower/newer ones so that the new-comers can just "sit in" and maximum pleasure can be gained all round.

My 2cents... (though we don't have 2 cent pieces anymore... I guess that should be "my 5 cents"...)