Feeling like I cant make him happy...

My SO likes to do anal which is fine but its hurts .e alot I don't mind working up to it, I have done it with him before, but I am always hurting so bad. I will use tonight as an example we were having us time, was giving him head then he decided to flip me over to eat me out, while he was doing that I noticed he was fingering my butt, this wasn't bothering me which is unusual and I was enjoying it then I started feeling uncomfortable and I said get that out and tried to get his fingers out well instead of taking them out he put them in further and fast I said ow it hurts, he asked what hurts, well I don't really know how to explain it to him besides my butt hurts. Then he got up pouting because I couldnt give him what he wanted and now I fell like crap and idk what to do to make things better in thay aspact so maybe he'll be a little happier.