Hello, I'm Alicia. Thanks for your question, I'm happy to help you today. I don't think there's any real "right" answer to this question -- ultimately, you have to do what will make you feel most comfortable, of course. If this is something that is going to bother you and will be constantly in the back of your head, then you should tell him, but I don't think it's necessary. If I were in your shoes, I might not mention it unless I felt compelled to, because you said it was just casual dating -- so I don't think that really falls into the category of a relationship. When your partner asked about your last relationship, I would assume he meant someone with whom you were serious, someone who you had a real emotional connection with and would therefore would fall into that category of a relationship. Either way, I don't think it's anything to be hugely concerned about -- whether you do decide to tell him or not, I can't imagine that it will really bother him one way or the other. Best of luck.
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