Where can i get a proper sectional cover that does not have to be tucked-in where the two parts meet?

Question:one section is like a loveseat with one handle, the other is like a couch (3cushion, one handle) but the end rounds off at the back to meet the open end of loveseat section. So its really two sq cushion and one pie-shaped (like two slices pizza together) cushion for the couch section of it

Answers:
Hire a seamstress to make a slip cover.