This question came up at a club I fly at recently, two guys looking to share the time. Provided they were both checked and current there was no problem. However, I remember one of the guys being right hand checked by an instructor round the circuit to ensure they could competently t/o and land the thing in the right hand seat which they were happy to do. As long as you agree the block time break down between you both and inform the club what you are doing, there should be no problem.
WD