Need your input. Chlamydia or UTI?

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I was just thinking about when my boyfriend and I first got together and I got a urinary tract infection. He asked if he should take antibiotics too, like I could give it to him or something. I told him no, that doesn't happen and he told me his ex girlfriend got a UTI and he had to take antibiotics as well. Do toy think she gave him chlamydia and didn't tell him? He was only 16. I don't know if I should ask him or not