Don't be a pussy man. Just man up and do it. Nothing disgusting about it. If you want to receive it yourself then you need to return the favour.
Not doing so is just selfish. I'm a dude, I always respect my lady and want to make her feel good. If she's worth it - Do it. If she isn't - Then you shouldnt be with her anyway.
Moral of the story - Be a man about it.