When you're dating or hanging out with someone new, exclusivity is generally not the major topic of discussion. However, if it's been a while and you're not interested in meeting other people, being exclusive will most certainly come up. If you say you're only seeing one person, then you should mean it. If you tell me you're exclusive but then go on another date with someone else, I have no choice but to believe that you're just trying to hurt my feelings. That's not fair and it's not nice. So don't do that. Exclusivity is important in a relationship. It's normal to want to be with one person only, but if you find yourself thinking about others even once during your time with me, then we aren't a good fit. I hope you understand why I'm saying what I am, and I look forward to hearing from you soon!