People are saying he's being a bad guy, but I think there needs to be a bit more of an open look at this situation.

First, you guys were previously involved in a physically sexual relationship. Everything was fine and dandy.

Now, either you or him, moved away and are not able to engage in the same sexual relationship. You don't want to engage in phone sex/sexting, while he does. So, he's been badgering and bugging you for nudes and phone sex. If he's in the mood often, and you guys were previously having sex all the time, he really hasn't changed his stance. Now he's just being denied the gratification.

You are both entitled to get what you want, though. If you don't want to sext or have phone sex, you are completely within your right not to do that. That is an answer he can either accept or not.

The reality of this, however, is that he seems to have an itch that isn't getting scratched. This may create a rift in the relationship and he may become resentful. This change may have him seeking relief, if you will, with someone else.

The end result is that this may be a dealbreaker for him. Long distance doesn't seem to be working out for him and you should be up front and honest to him about how you feel. Don't say "I'm not in the mood," say "I do not like the idea of phone sex or sexting and will not partake in it." You have to really make it clear how you feel. From there, you can talk about the relationship with him and how you two can compromise, if possible.