The prone/lying down version of pigeon can really wreck me - very risky for my knee. The standing variations can feel good, but has still proven risky for me.
This stretch is deadly for my hip, believe it or not:
I can probably go perform that stretch and F my hip up instantly.
This is the only hip/glute stretch I still do, it seems to be the safest for me. Also, instead of flexing the off knee more to bring the stretched leg closer to me, I just twist towards the off leg a bit. If I bring the stretched leg closer to me, seems more risky for my knees.
When I get annoyed that a stretch is risky for me, and try to improve that mobility/flexibility, I always get hurt.