"And they'll tell two friends" bugged on steam (Not Enhanced)

[deanyo7]

I’ve met all the criteria to get this achievement but it still wont unlock, I don’t know what else to do because i want to 100% this game but i can’t if this achievement is bugged which would suck.
(This is on the original GOTY version not the enhanced one)

[VaultHunter101 (So long, and thanks for all the fish)]

The only criterion is to play with someone who has unlocked the achievement already on the same platform. What platform are you on?