My parents offered to host most of the reception (gave me a set amount of money to work with). Our plan was to use that and then cover the rest ourselves.
My FI's parents are divorced (and it wasn't amicable, and they never interact, even when it comes to their children). They are both in other relationships now.
My FFIL and his wife have offered to help cover the rest of the costs (though we won't let them cover everything, but it was very nice of them and we are super appreciative). However, when my FMIL spoke to my FI on the phone about the wedding, she told him that if he needed anything to just ask his father (note- he didn't ASK her for money- this was just her response to talking about the planning phase). So as of now it's a joint hosting by my parents, my FFIL and wife, and ourselves.
I am very unsure of how to word the invitations for hosting the reception and wedding in a way that won't hurt my FMIL. I'm close to both of his parents, and I don't want that to change!