I notice from my own dealings with such types, that it seems to be a trait of the fallen nature, that once they get a little friendly with you, they see it as an opportunity to "use you" for their own selfish reasons,not caring if they inconvenience you, as long as it benefits THEM.I've had this problem.Wonder if thinking of yourself at others expense,is a sin? Well, I would think the sin here is selfishness, because if you explain to them that its a bad time, they "press it", thinking of themselves over you, like they're the important ones, and you don't count.Or not taking no for an answer. So I would think the sin here would be selfishness, which is the motivation .{These aren't things they need , it's more a convenience to have you do it instead of them. }But because of the selfish motivation, is that considered a sin? I think so.