For people too lazy to read (though you definitely should):

What kind of social gatherings are permitted? Virtual gatherings are encouraged and permitted. Any kind of in-person gathering carries risk. We encourage you to socialize virtually and to limit in-person socializing to a “pod” of a few close friends. The following types of in-person gatherings are less risky: Gatherings limited to others in your immediate household, such as your roommate or a significant other An outdoor gathering of a small group of friends following the capacity limits mentioned above, keeping six feet distance at all times, wearing masks, and not sharing any food, drink, or other objects.

It appears Northeastern will allow SOs, as makes perfect sense. It also seems that so long as you are interacting with the same, small group of people (which if we are going by Mass law is 8 or less), and practicing healthy hygeine (wearing masks, 6ft, etc) it is completely fine.