Ruling on pants with fallen drops of urine

Having OCD I usually avoid washing my area immediately after urinating otherwise it leads me feeling urges to urinate again and it's really frustrating that's why I let the area to relax for some moments and don't touch it. But the problem is when I stand up after a suspended drop left falls randomly on pants. Now I can't even wash that area because I have my pants lowered and am only left with washing the whole pant. Is there any measure I can adopt to this. Or can I be excused in this matter for not trying to prevent the drop? I don't do so because of the fear of further obsessions and they're really annoying compelling me spend a plenty of time in washroom.