[s3e5] Old Flame Direct

If you were referring to a different popular show where the fifth episode of Season 3 has a major plot point involving an "old flame" or similar drama, it might be one of these:

Meanwhile, Carol seeks revenge on Lillian for an old affair by reporting her as a benefit cheat, and Carl finds himself in a messy love triangle involving Lip. Other Notable S3E5 Recaps

Kevin panics because he previously told his current partner, Veronica, that he was divorced from Roxy, when he actually never finalized the legal paperwork.