Girls, Ex girlfriend confusing me?

Me and my ex girlfriend who were together for 5 years and we broke up because I had a smoke after I said I wouldn't do it anymore but she been dating her rebound last 2 month but we see each other everyday and flirt with each other but she now wants me to come over and do a drug test for month she not interested in us getting back even though we still sleep together. I think the question I'm asking is why would she want me to do a drug test if she dating another guy?
Girls, Ex girlfriend confusing me?
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