He is absolutely not entitled to have any expectations that you will be willing to host him, but I think if you invite him to stay over - and invite means "agree to host him", then you are obligated to treat him like any other guest.
The place to draw the boundary is on the doorstep, not once you have invited him in. If you say, "well, yeah you can stay over but...." and put a lot of conditions on it, like unusual expectations for meals, or whatever, then you are just making a weird situation any wierder.
He's a guest, or he's not. You and DH just have to be on the same page on that and decide.
I think I disagree. I think that doing a favor for someone by allowing them to stay over when they ask is different from a guest I invite.
I'll go out of my way for a guest to assure they are comfortable. Some one crashing on my coach gets a pillow and blanket and needs to get out when I say.
I think I'm w/ Hmmmm on this. I do think that offering supper was required, given the time of day. But there are degrees of "people in my house," and Cousin Couch Surfer isn't really quite a full guest.
I can see that, and I'm not saying OP should iron the bedsheets and put out the fancy towels, but I do think there are certain minimum obligations of hosting - and if you agree to have someone in your home, you are their host. The guy did not
break in.
One obligation - you do not eat or drink in front of a guest without offering them something. OP met that, and I think that obligation continues if she hosts him in future. Another would be that you do not intentionally make your guest take the leavings, or a second-class meal. A drop-in and there's not enough to go around, is one thing. But if OP were to get up and make bacon and eggs for breakfast, it would be rude to make just enough for her and DH, and tell Cousin "here, you can have a cold bagel."
If they were to open a bottle of wine with dinner, it would be rude to only offer Cousin water. If they are sitting at the table, you don't tell Cousin he has to sit elsewhere. That kind of thing was what I was envisioning.
I don't think she needs to do more than the minimum, but there
is a minimum. And if that is too much for you to do, then you should say "no, you can't stay over".