Background:
I have an upcoming business trip to South Africa, going to try out the ATL-JNB flight (Y

) The wife is going to come along, so I was going to book on same PNR (Wife has no status, I'm GM).
Turns out instead of returning home, I need to go to Beijing first, before going back home. Pricing gets pretty bad on this, as R/T U.S.-JNB has sLUT availability for subject dates, while one/way prices in Y, almost double R/T.
The question: If I book 2 people R/T U.S. to JNB and back, is it likely to cause any problems if only one of them checks in for the return trip? Specifically for the one who does travel back?
Thanks for any advice.