No you shouldn't 'have to' accept it if it displeases you...and that is totally up to you. However, I feel I need to play 'Devils Advocate' here. Dating another person shouldn't mean that they are to socialise exclusively with you, not have friends of the opposite sex..trying to enforce this as a relationship condition is a sure fire way of alienating your boyfriend imo. Be confident in knowing that he is with 'YOU'...I'm not saying he won't ever meet someone that he prefers along the way, but that is part of dating...trying others on for size. Sure I know it sounds harsh, but that is life.

Just be happy dating, and focus/capitalise on making the most of what you have in common, and what you like about each other NOW...not what may or may not happen in the future.