My partner and I are very secure in our relationship and have absolutely no problems having close friends of the opposite sex. I get along much better with males and have had far more close friendships (or even less-than-close friendships) with them than I have with females. I know that several of my male friends would like to sleep with or date me, but I'm open about it and tell my partner, and he doesn't have a problem with it. I mean, I also know that one of my female friends would like to be with me, so if the possibility of attraction was an issue, I simply wouldn't be able to have any close friends but my partner, and that wouldn't work for me (nor should it be an imposition on anyone else).
Despite the fact that we're currently long distance again, he trusts me absolutely and knows that though we have an open relationship agreement, I have no desire to be with anyone else either physically or emotionally. I would never be with someone who had a problem with me having close friendships with males, because I think that it's absolutely ridiculous to try and control people's friendships unless they're harmful or destructive. I know that at least one of my partner's female friends wants to date him, but he told her no and as far as I'm concerned, that's the end of it. If she has a problem with that, I trust him to deal with it. There may be some jealousy there upon occasion, but we're open about it and it has never been a problem.