I like her and this other guy also like her too?

I know this girl for about 10 months now, I like her on an intimate level and it seems like she likes me too but there's this other guy who's a competition for me as he also likes her. I am jealous and hesitant because he is taller than me, I'm 5'8 - 5'9 he's 5'11 - 6'0, he's more popular, independent and older than me by a few years and had already initiated to flirting with her. What should I do? The way they talk to each other is almost as if they're a couple.

Ah man, wouldn't worry about height as much as it knocks your confidence I can tell.

Without too many details you could do numerous things, hopefully you've been flirty with her before though.

It's a tough spot because unless you've been that way towards her, she may think you have no interest or you're a friend. Which is difficult to climb out of and honestly if someone has a shiney interest it's hard to divert attention, as right now for her it's almost like a new toy.

When you're having a good chat with her, drop in that you'd like to go for a drink or something. Maybe do something fun with her. If she passes then it's a matter of moving on, but if she says yes then you go from there.

Sometimes the only way to settle your mind is taking that step.

You waited too long. Some other guy got to her before you did.