Yes, it is absolutely okay to reject a guy before the first date if you feel that you won't be compatible and that your lifestyles are fundamentally different. It's essential to be honest with yourself and with the other person about your expectations and what you are looking for in a relationship.
Dating is a process of getting to know someone and determining if there is potential for a meaningful connection. Sometimes, even before meeting in person, you may have gathered enough information about the person's values, interests, and lifestyle through conversations or online profiles to realize that you are not well-suited for each other.
By communicating your feelings honestly and respectfully, you are saving both of you time and emotional energy that might have been invested in a relationship that ultimately wouldn't work out. It's better to be upfront about your concerns and preferences early on rather than leading someone on or going on a date with the knowledge that you're not genuinely interested.
Rejection is a natural part of dating, and it is essential to handle it with kindness and empathy. Be polite but firm in expressing your decision, and avoid being hurtful or overly critical. It's better to be true to yourself and pursue connections that have a higher chance of being meaningful and fulfilling for both parties involved.