<human>: Provide a brief overview of the text.

Hello, last night me and my girlfriend had sex for the first, which didn't go too well but that is a question for another subreddit. 
The next morning, we are fooling around, play fighting and what not and she calls me by another boys name.

I know for a fact that this boy (the name she called me) has been sending her messages like "I think I'm and love" and sending her messages all throughout the day. 

She will not let me read her phone, nor will she tell me what this boy is telling her, only that, he is being a dick.

She was distraught afterwards, close to tears, I had to calm her down, telling her it didn't bother me.

It really did, I need help.
<bot>: My girlfriend called me by another boys (who she is currently in contact with) name! Am I being played? Who is this guy? Should I be worried? What should I say to her?