Redecorate your (or his) room in sissy pink. Give a real feminine touch to his bedroom by changing everything to pinks, whites, laces, and flowers. Make him really feel like he's living in a completely feminine room, sleeping in a princess' bed, and getting ready in the girls powder room.
If you share room, you will finally have the decor of woman's dreams, and he will finally know that he's been subject to live in a completely feminine environment. It's a sweet subtly way to remind him night and day of the girl-power, and the sissy he's resigned to be treated like.
You can tell him that since he acts like a girl, wears girly things, and is treated like a girl, then it's about time that the room reflects that.
Change all the towels and sheets to sissy pink colors. Make sure the bed is full of lot's of white and pink fluffy and lacy pillows. Line his drawers with lacy pink and white cloths. Change his desk or dresser table to be full of lace, pink things, and flowers.... just over do it and make everything super feminine.
You should do this as a surprise when he's away. When he comes home he should find that he has no choice but to accept the change in decor.
Don't let him have any sort of masculine or neutral decorations in his personal environment… make sure you get each detail feminized.