I don't think they should be able to tell you what you can or can't do outside of work.
However, I think you should be responsible enough to not put yourself into a possible quarantine position.
For example, the best solution is to not have something like that at all, or at least use virtual table top available on Steam.
Next best solution would be to have it outdoors with masks and physical distancing. Third best would be to have it indoors with open windows, masks, and physical distancing.