Is friendship with the opposite sex possible while dating?

I've been dating a guy for almost 8 years. As with everyone, although we have similar interests, there are still things one likes to do that the other does not like. We recently made friends with a guy that, as me, likes to surf, skate, discuss poetry, and other things that I otherwise wouldn't do alone. I hung out with him a few times, sometimes with my boyfriend, sometimes alone. I'm having a great time doing things that I hadn't done for such a long time, but now my boyfriend thinks I'm going to cheat on him or leave him for this other guy. That is entirely not the case, he is only a good friend to me. I can't help but thinking that if this guy friend were a girl, then there would be no problem... I'm now unsure if I'm doing right or wrong. Or if I should stop meeting him alone (problem is, I don't know anybody else who likes to surf or skate to come with us). Or stop this friendship altogether.

If you guys met and befriended the other guy when you were together, then you need to spend time together as a group, rather than you spend time with him alone, regardless of the reasons why. You need to understand that it's your actions and the extent of them which is making your BF insecure and that alone should give you a 'heads up' as to whether it's right or wrong. You're correct, if your new friend were female, there possibly wouldn't be an issue, but, after 8 years of dating, you guys together as a couple, should have an idea as to where and how your relationship is going.