“There is nothing in the Massachusetts Condominium Act—Massachusetts General Laws Chapter 183A—which would restrict your boyfriend occupying the unit. If the community has any type of rental restriction, you could look at that to see if it prohibits your boyfriend from moving in but I would doubt it. Any condominium document restriction that permits one family or not more than 2 or 3 people unrelated by blood or marriage is likely illegal discrimination based on familial status and it appears you are only having two occupants so it is very likely not an issue.
“This being Massachusetts, it would not shock me if the so-called Blue Laws–very archaic and puritanical laws–might have at one time technically prohibited you from having your boyfriend live with you but they would not likely ever be enforced even if still on the books. If in doubt, ask your association.”