an enthusiastic expression of confirmation, addressing a question that could not merely be answered with a simple "yes;" can be extended to "ohhhhh yeshh" or "ohhhhhhhhhhhh yeshhhhh" depending on the extent of enthusiasm
1. Shayna: sleepover at your house??
Lizzy: oh yeshh
2. Me: shnuggle and eat shnackies??
Wifey: ohhhh yeshh!!