Hi all

In the near future, I am intending to make a journey from Brockley to
East Croydon, to meet a friend coming from Gatwick Airport, and then
bringing him back to Brockley. How do I do this with Oyster?

Do I just exit at East Croydon, then immediately enter again? Will
this give me two separate journeys, or will I confuse it with an OOSI?
And what would happen if I touched in at Brockley, then did nothing
else before touching out at Brockley an hour later?