golf clubs showcase

We were short of the green, on our approaches. I was about 8 ft from green and my flight mate was 5 ft directly in front of me. I was not feeling confident of chipping or pitching there and then, and i was really thinking of putting the golf ball in (fringe and green was quite flat). But the prob was my flight mate was on the line. So, juz curious as to whether can I ask him to mark his ball, and perhaps even shift the marker by one putter head length, as per on green?For that scenario, my flightmate flatly said cannot, and I dun wan to argue. Ended with a lousy chip and 2 putts. Thinking back, really may have a better chance to par if i putt in (properly)...