The Bad - Cycling, especially with certain seats and handlebar arrangements, can cause a lot of pressure in the perineum
The Good - Certain seats and maintaining your handlebars at a lower level than your seat lessen the risk
I don't have the sources I originally looked at (this was several years ago!) but a Google search pulls up some that jive with what I recall.
https://www.health.harvard.edu/blog/biking-and-sex-avoid-the...
https://www.health.harvard.edu/staying-healthy/can-cycling-c...
https://www.webmd.com/men/features/biking-and-erectile-dysfu...
