her reply: "Iv'e been seeing this guy for a few weeks"

I've been writing to this girl recently and then decided to take things futher within the 3rd message i sent her i have come across a bit of a problem. Im going to go away and have a think, but i thought id post it just to get other opinions if i can?

well i wanted to mention this earlier but wasn't sure how.
I think your incredibly sexy and would love to spend a
night hanging out. eating food and genuinely getting to know you sometime soon,
if you think you can handle it........ when are you free?

Hey sorry I didn't mention this earlier but I've been seeing this guy for a few weeks and even though I'm not ready to take it public or anything - I really want to be exclusive with him and just see how it pans out xx

Sorry bud, he might of got there before you. And there would be nothing you can say or do. I say might because he could still screw this up and they are not 'official'.

I would just keep pushing it, if I was interested saying stuff like your potential boyfriend sucks. Or you could keep her as friends and be her rebound, you can get sex like that too. If she's got any good friends you can pull just say, No problems, sure lets just be friends and invite her out as 'friends'. Otherwise I'd just let it go because there are literally billions of other woman out there.