It would depend on how it was presented. If the giver of the fake ring tried to pass it off as a real one, then there would be issues. If they said it was a temporary thing b/c they couldn't afford a real one, then that would be different.
Funny and related story:
There was a tiny little blond cheerleader at my high school who dated a freaking huge football player. He got her a "diamond" ring and told her it was real. But, pretty much everybody in the school except for her knew it was a fake.
There was a segment on diamonds in her chemistry class a couple of weeks after he gave her the ring. They were talking about how to tell if a diamond is real by shining light through it and looking at the Prism-y pattern and sparkle and such. A few minutes into looking at their own jewelry, this girl raised her hand and asked the teacher (who also knew it was fake) if her ring was sparkling. He told her that it wasn't.
She spent the rest of the class slumped in her chair with her arms crossed over her chest. Her boyfriend would always meet her outside the class and walk her to her next one. When she didn't come out after class was over, he walked in to find out what was going on.
She popped up out of her chair and stuck her hand right in front of his face and said, "It's. Not. Real!" Stupidly he said, "Yeah...so?"
The tiny little cheerleader took a swing at the huge linebacker guy. She decked him so hard that she completely knocked him out cold. The guy fell flat on his face and she walked
over him to leave. She said goodbye to the teacher and flounced out of the room.
The next class came in and saw the guy on the floor, so they asked what happened. The teacher told them that the girl finally found out her ring was a fake. They all got a good laugh about it and the guy finally came to a few minutes into the class.
