1 Problems that people with active sex lives have.
2 A retort to someone who complains about the consequences of getting lucky.
A: Ugh I ran into two people I've slept with today.
B: Thirst world problems...
Problems that are only experienced by people with an abundance of admirers and/or partners.
"That guy I was flirting with wants me - but he won't date polyamorous chicks." *Sulks*
"Oh honey you've got thirst world problems!"