My mother's only sister has been married to my uncle my whole life and they have three sons who I was very close to when we were growing up, until the family moved across the country. The past 2 years, my aunt and uncle's relationship has been rocky and involved a lot of fighting. A few months ago, they decided to get a divorce; they both travel a lot for work though, so they still live at the same house, but are almost never there at the same time. My cousins blame my aunt for most of the problems, and since they're all in college or grad-school, can't afford to pay to come to the wedding on their own. My uncle said that if he comes to the wedding, he'll pay for my cousins to come too, but my aunt already told my mom she was coming alone.
Is it okay to invite them all? And if I do invite both my aunt and uncle, do I send 2 invitations or just 1, since they're at the same address?