Upvote:3
You won't be able to :
TIMATIC (the database that airlines use for documentation) state :
Romania - Destination Visa
Visa Exemptions
Passengers with a “C" visa issued by Bulgaria or Cyprus, valid for the period of intended stay. They are visa exempt for a maximum stay of 90 days.
The maximum stay is granted within 180 days.
A single entry visa becomes invalid as soon as you have used up that entry and leave the country. You can either invert your itinerary and go to Romania first, then Bulgaria, or get a Romanian visa