Sideslip and swept wings
While a student pilot, I had the opportunity to get a bit of dual in a Ryan PT-22 (civil designation ST3KR). It had a very slight sweepback - no more than 5 degrees - to compensate for a lighter engine than earlier models.
Because it had a good reputation for aerobatics, I wanted to do some slow flight and stalls for familiarization. We did a few straight-ahead stalls, power on and off, and it seemed straightforward enough, good buffet warning, easy recovery.
Then my instructor (Prof. Irwin Treager, who wrote that terrific turbine engines text) asked me to try one with just a bit of cross-control. The approach to the stall was normal, but it didn't just break - it suddenly snaprolled 360 degrees before I had a chance to respond!
Treager had taught a very good lesson that day - even a little sideslip paired with a little sweepback can get ugly in a hurry.
Moth and Harvard pilots can probably confirm this.