P trap for 2 drains?
Under IPC (and probably other codes) anything other than &quot;a double sink&quot; with various short distance restrictions on what constitutes that requires its own trap.
https://codes.iccsafe.org/content/IPC2018/chapter-10-traps-interceptors-and-separators
1002.1 for the detailed language, but the short and sweet is you might be able to share a vent, but each needs its own trap.
Furthermore (under UPC, apparently not a problem under IPC) you are not allowed to put a laundry P-trap under (or within 6&quot; of) the floor, which would work against sharing with any normal shower drain.