Search Results: how to flirt online relationships

Ok so me and my boyfriend have been online dating for almost 3 years. I love him so much and we consider our love and relationship to be real and serious well he says I'm his first girlfriend ever and that he never had a relationship before me. Well I remember him on another website (the one where we met from) before we started talking dating flirting and sending out flirt/love emojis and saying how awesome she is. When we first started he said she was his ex and that they made an agreement that when they found someone in real life that they'd break up. Ok, fast foward to 2 years of us being together he says that I'm his first and that she was a *pretend gf* and that made me think what am I to you then? He said I'm real and that I'm his first girlfriend ever he made me insecure, jealous, and made me have trust issues. I used to bring it up and get angry at him everyday for it til the point he said that same things over and over to be that I was his first that I calmed down but every once in a while it still eats at me and is in the back of my mind. Like today I was showing him my new laptop and I said "let me search your username on google to see what we'll find" then I seen what I saw a long long time ago that pissed me off his Yahoo answer profile with him flirting w/ that same girl. I couldn't help but click it and got annoyed which said he was last active 4 years ago. He was telling me to get off but I got upset and over reacted and was questioning what a pretend gf/date is. He hung up on me and I was calling him back and we talked a little. I got upset and started crying. I asked him if I messaged her and asked if you guys ever dated what would she say he said "Idk". I don't care it's just the fact he said "pretend gf* and said I was his first girlfriend.. It doesn't make any sense to me? I don't understand. What do you think and did I overreact or would you feel the same way I do? He just hung up on me and said his phone was dying even though I was crying. I think he fell asleep.. I feel bad now

This gagger and I used to be in an LDR relationship but things didn't work out in the end due to the distance issue. Then we started talking again and flirting a lot until he told me it had to stop because he just got a girlfriend where he lives. So i thought okay cool, fine, we still talk every single day. But some girl just popped up on gag a few days after he told me got a girlfriend, she immediately followed me after making her account it seems and is barely following anyone else, she only ever responds to his posts, even when she asks questions on here she only responds to him. Turns out its his girlfriend after I asked him.
She's online very often but barely comments on anything, pretty much mostly does when he's commented somewhere or when he's asking questions.
Another note is before she started following me he would be all over my feed making personal jokes and comment on most of my posts and questions, now he barely doesn't at all, even though we still talk privately.

Am I just over thinking things or does she know about me? Could she possibly have made the account to stalk me or perhaps stalk him I guess?