I agree, I don't really consider writing "dirty words" to someone cheating, unless they've actually touched them, I don't think it's a big deal. I think it's tacky, and more than a little childish, if you have to get off by telling someone how much you want something that you can never have, yeah it's sort of sad. But not the same thing as having sex with someone else. Now if I found a text my bf sent to some tramp and he was actually making plans to go bang her, it's on.

As what the OP said, "texting sexual things to other girls" ...... I believe it is a malicious thing to do, this could be a fire starter, from dirty talks to flirting and what else may follow, one thing could lead to another. So, if you will just let your bf do it without warning him to stop , it could destroy your relationship. Texting with out any malice or sexual innuendos is ok as long as you are sure it's just a friendly conversation with a girl, there is nothing wrong with that because both of you have a right to communicate or make friends with anyone as long as you know what your boundaries are.