My boyfriend thinks I looks more pretty during a headache.

My boyfriend tells me I am more pretty when having a headache, especially migraine. It may sounds weird. I've been living with him for 2 years. He loves me and doesn't want me to get hurt. But he considers the way I press my temples hard and endure pain sexual and strong.
Take these photo for example: https://i.imgur.com/MmItAv2.jpg https://i.imgur.com/KwKpVk2.jpg
He even offers sex during my headache, which is actually helpful to relieve my pain.
I can tell you he's more a masochistic than a sadist. Sometimes I even found myself looks better during a migraine.
I don't know why is that exactly. Does anyone of you know someone with similar ideas? How am I supposed to cope with him and these feelings?