When I was younger I didn't really suffer OCD. My Dad was always particular about strange things, one of which is that he doesn't like others to use the same hand towel as him. These peculiarities used to really piss me off and I'd sometimes give him shit about these things. Now that he's much older and I've grown up I am far more respectful towards him. Now when I visit him I take into account the things that bother him, for example when I arrive I'll ask him if he'd like me to get out a hand towel for me to use. I've noticed that now that I take his concerns seriously, he is less OCD about them. For example, since I have been asking him about the hand towel he no longer minds if we use the same one.
What is it that has changed for him? Why does a concern of his seem to cease being a concern now that I too am concerned about it? Perhaps he thinks that if I too am the kind of person who cares about sharing a hand towel with dirty handed people then he reasons that we must both be clean handed people, and can therefore share with each other?? Perhaps the concern is caused merely by a fear that something which seems to him obviously of great importance is not being recognised as such by others, and once he knows someone else is looking after the issue he no longer needs to?? Perhaps it's a trust thing - he trusts that I care about what matters to him, and that is enough to end his anxiety about it??