Best definition
Younger Sister Syndrome (YSS)
When the older/oldest sister of a family oftens engages in a relationship out of spite of her already engaged or

further advanced younger sister. Generally moves in with her new man, gets engaged, married or pregnant all within the span of the younger’s term of engagement. In the long run, not a wise decision.
Most people have witnessed at least two of these instances. General outcomes of “YSS” include but are not limited too:
1. a jailed husband (physical abuse, drugs, theft, video taping women at work, etc..)
2. A miserable 6 month marriage
3. single motherhood
4. self pity

Observer #1: “Jamie moved into her man’s house, got pregnant and has quit her high paying job all since her younger sister LeAnn got engaged to her her long time boyfriend.”

Observer #2: “yeah, I heard her man has a ton of great qualities like…well, umm…nevermind. At least he drives a nice truck”

Observer #1: ” Another victim of the Younger Sister Syndrome (YSS)”