Holy shit buddy, that's a lot of assumptions... I text my friends' girlfriends all the time, because news flash: You can be friends with someone of the opposite gender without being romantically involved with them. That being said, OPs case is obviously worse off, but that doesn't mean the friend was sexting her all day.

Sorry but your an idiot and either don't know how to read, have terrible social skills, terrible friends, or poor morals (or any combination of the above). As was mentioned above, you can have friends of the opposite sex without wanting sex or having sex with them (I'm a guy and a lot of my friends are girls but I don't want sex with them because I have a girlfriend I love). Also, if what your saying is true why would his friend even text him at all? And seriously you must be super insecure if you want anyone your significant other texts to text you right away and be like "oh shit, your ______ is texting me"

Holy shit, 33, I feel sorry for whoever dates you. You sound like one of those people who checks their significant other's phone and doesn't let them have any friends. Assuming is one of the worst things you can do in a relationship, and you sound paranoid and mentally unstable.

I bet it was an exaggeration. OP's friend sounds more like he's annoyed by the girl than anything else.

Why should he dump his friend? His friend did nothing wrong.

I'm guessing the friend had been texting her back all day, too. Maybe she is one of these demented people who will send multiple consecutive texts without any response (it seems like the OP has this disease), but more likely is she and the friend had been flirting all day.

Ha.