I vote you keep doing what you're doing, be friendly when he is and if you are one-on-one with him flirt like he's a stranger that you're interested in (which he basically is).
Me: 34 W:33 T: 10 M: 6 S: 6 D: 5 BD: 5/14 Still together(ish) Not giving up: 7/14 D talk has slowed, a lot. Gradually working on things together. Still separate bedrooms. Slow and Steady wins the race.