I didn't let son/25 and his g/f 21 live under our roof and what to do now?

They both lazy, untidy, cheaters, liers, rude and manipulative, never saved any money, make new debts right now. They rented apartment brefore and after 6 month ended with many thousand debt. Because I didn't let them live in our home my husband is pushing them to marriage and said he will pay their rent. We are old and we do not have almost any savings. Because for them all I am that witch who doesn't support beautiful love I decided not to go for their engagement party. Am I right not wanting my husband to support them financially and not to go to that party?