My colleague is a male, single, in his 50s. I'm in my late 20s. He's an expat in my office, liked by other colleagues for his nice & culturally-sensitive attitude. Sometimes he's even more sensitive than the locals. Bad news is he recently got mild stroke & has been feeling down since. He often thinks that the stroke makes him useless professionally and people are trying to kick him away. I don't see that happening and I think it's just in his mind. Anyway, as a colleague/friend, since the stroke, I've been offering some companies when I could. I listen to his stories. We went to art exhibitions, movies, dinners, etc. I just don't want him to feel negative most of the time. However, lately I sense that he might misunderstood me. He becomes possesive. He would become uneasy when I turned down his invitations, he insisted to see me after work, he instant messaged me at home. What should I do? At the same time I don't want to hurt his feelings considering his condition.