Closing doors

Just wondered if anyone had any idea how I could crack this one.  My boyfriend’s allergic to cats.  He can get up close to them and stroke or play with them but if he spends too long in a room with a cat he gets congested and has trouble breathing, especially at night.  I used to let my cat on the bed but since he’s been coming to my house more often I’ve banned the cat from my bedroom at all times. 

Last time my boyfriend was here I didn’t shut the door straight away and the cat ran straight in, so I put a sign on the door that said ‘SHUT DOOR, KEEP CAT OUT’.  I still managed to leave the door open at least once that weekend so I put a sign on the other side of the room  so that  I would see it as soon as I came in.  The next evening I left the door open again. 

Each night I’ve been lying there imagining opening the door and closing it again and cultivating a feeling of urgency to try and carve the memory into my brain.  I’ve repetitively opened and closed the door while again attempting to attach strong emotion to the action (fortunately only the cat was witness to that one but he looked most confused) and even written lines.  At one point I slammed my hand in the door in desperation.  It wasn’t just anger; I was hoping it would get me to think about it and close the door next time.  I still left it open.  There’s now a sign taped to the edge of the door that waves at you like a flag as soon as you open it.

My boyfriend has a stressful job and has trouble sleeping at the weekends.  I want my house to be a restful place where he can have a break before going back home refreshed.  Really, he badly needs a holiday and an escape.  Until then, just being able to sleep would be better than nothing and everyone knows what it’s like to try and drift off when you can’t breathe comfortably.

Has anyone a method for people with adhd to remember to close doors?