Guys are loving yet competitive little creatures. We want our buddy to be happy, just not overtly happier or luckier than us. For example, if a guy walks into a party with his new lady friend and she is a drop dead bombshell Ph.D. heiress with Chris Rock wit and the sports acumen of Bob Costas, we'll probably sh*t talk and shun her due to our own pain. If, however she doesn't threaten our own egos, but rather supports and gently lifts the general status quo, we are very accepting.
This might sound harsh and ugly, but it doesn't make it untrue. Guys can get all Darwinian with each other despite their friendship. Adding to this, some guys bring aorund so many girls (booty call kings) that its not worth his buddies time and energy to get to know "today's gal".
"Hey, Steve where's cute Ruthie, the marine biologist?"
"Who's Ruthie?" he answers back.
Lastly, there is also a strain of friend that is overprotective of their friends. They approach new women in their friend's life with great scrutiny and judgement; as if their little prince is too good for anyone. "So where did you say you graduated from?" "What subway stop do you live at?" "How long did you say you'd been single for before you met my Steve?"
So all and all you can see there are too many ego and personality factors at play when trying to answer your question with a clear "like" or "dislike" answer. The only real answer is don't worry about the impact of your splash; if you're met by piranhas or giddy dolphins it's likely not even about you.
My boyfriends best friend is the over protective sort, and he has a huge ego. I felt like I was being interviewed for a job in the CIA the first time I met him. I mean he was asking me about my parents income and how they voted for crying out loud. What's funniest about that is that my boyfriend and his best friend are on different ends if the spectrum politically, some I'm not even sure who's criteria he was judging that info on. And then he was asking me my thoughts on 1920's vaudeville, and my career goals and what sort of climates I like to live in. It was insane. I didn't let the third degree trip me up, one of the perks of acting an improv training, I'm pretty good at rolling with the punches, but I couldn't believe he actually felt he had the right to question me like that.
"what sort of climates I like" That -- is fantastic.
My former boyfriend took me on a group date for one of our first dates. His best friend immediately scrutinized me and asked about my parents income, what parents jobs, my political views and my views on relationships and the issue of "who should pay".
Once I gave him the answer that I thought it should be split especially while we are in college and when the relationship is at the end of the honeymoon stage, he criticized my views on women and equality.
Then he threatened that he wouldn't be afraid to hit a girl.
After seeing the look of shock and confusion on my face, he retracted and said "that was joke". It was very awkward and made me question my relationship with my guy. He also told another mutual friend that he felt my guy could do better. It eventually led to me feeling the need to break free from that and breaking up (mutually) with my boyfriend, I still cannot imagine going back to him (even if I do still have feelings) because of his friend.
Moral of the story is, do your best to make sure you at least have a civil relationship with his friends, but if they are truly the ones refusing to accept you, you must accept that they are probably just that way and it is probably nothing that you are doing. You have the choice however to put up with it or to let the relationship go.
My boyfriend's best friend is a girl, so she was SUPER critical of me. Fortunately, we all worked in the same place, so she had gotten to know and like my before I started dating him. She was actually one of the people who enabled our relationship. :)
I've actually become absorbed into my guy's friend group, and I love it. I mean, I have friends outside of that particular circle, but I've gotten to know them all as smart, hilarious people. We've formed our own friendships aside from my relationship with my guy. If possible, I'd highly recommend it. If not, just be yourself, and also understand that both he and his friends need their time together, too.