My BIL does this. He had "headaches" for years until his GP did some serious tests and told him they were stress and depression related.
Now he has "migraines" but won't even try any migraine medication (could that be because they're not migraines?). He spends all weekend in bed watching tv while sil looks after 2 boys age 4&6.
He's told dh he knows he's depressed but antidepressants are "rubbish" (tried one brand for 2 weeks about 8 years ago).
He came to stay with us about a year ago for 5 days - immesdiately went to bed (after getting our wifi key) and spent 4 out of 5 days in bed, loudly watching tv on his laptop. Only time we heard from him was when he was hungry or on the occasion dh turned off the wifi.
I understand that people get different kind of migraines - mine were hormonal, and I couldn't eat or watch a screen. He seemed to be able to do everything someone lying in bed for fun could do - watch DVDs, YouTube, listen to music, leave the (blackout) blind up. What really annoyed me is that we thought he genuinely had migraines so gave up our bedroom (which is specially designed for me, I have disabilities) and he was unhappy to let me in to use our adapted shower, as it "disturbed" him.
They won't be coming back until we can be sure this won't happen again. As a family we can't do it. No matter how much mil cries to dh that we "don't care". We do, it just hurts us too much.