Its a "DESI" thing and not "MUSLIM" thing becasue as per Islam after Nikkah there is no need to waste 100000s of $ on lavish wedding and girl and guy can constitute the physical relationship. Its the DESI oh "looooog kia kaheen gaay" thingie
BTW, personally I am not in favor of having "baat pakki" or "Mangni" or "Nikkah" for long time if there are no plans to actual "rkhsaaat" the girl. These relations are nothing but weak threads and when broken, these past relations really hurt!
Agree.