Get new riding buddies/friends it's the only way to stop this from happening to you. I had a friend, stuff me around constantly, always late, then he would have to pump up his tyres etc before we took off instead of doing these things before he left home. When finally ready, he would complain of feeling hungry and want to stop and eat before we started.
I don't talk to him any more.
I hate wasting time, it is one of my pet hates, traffic lights, cues at banks, checkout counters etc. Life is too short to spend it waiting for some guy to stuff you about constantly.
CHEERS.
Mark