It All Started So Gaily (1944)

Original title: Es fing so harmlos an

Clemens and Bobi, two legation secretaries, are sent on a delicate mission by their minister: it concerns a red portfolio with secret papers, which the minister stuck under a bed mattress and forgot about when he met someone on a rendezvous. And to make things more difficult, the horny minister can't remember which room he left it in. After several incidents in different hotel rooms, neither secretary has found a thing. There's not a trace of the portfolio; but Clemens is more interested in Annette, the young lady in one of the hotel beds, than in the portfolio. He forgets his mission and can think only of her. Boni, in the meantime, has found his way into a room, where Olivia is staying and sees a red, leather folder there. But the woman throws him out in short order.