It is not possible to sin and think that once I get confession I will not sin anymore because the regret has always be greater than the urge to sin. in other words the urge to stop must always be greater than the urge to continue in sin. If I know that something is evil and yet persist in doing it with the knowledge of getting confession, then it is very difficult to really regret the sin because if I really regreted it I would stop it now. I sometimes find myself in the very same situation. Some things I know are evil are just so pleasurable for example vanity gluttony egoism and one finds himself vindicating the sin or saying that it is not evil or not so evil but such Behavior is itself sinful even though I do not sin the way I’m afraid to sin- the sin I try to vindicate or persuade myself that it is not a sin. In this way i basically sin even before the sin itself- the one I tried to avoid.