Lol you have a gf? No offense but you're insulting the

out of her having that chics pic in your sig. Whether you know it or not pretty much all girls except for the teeniest handful have horrible self esteem, but are good at not showing it.
As crazy as it sounds, if she saw that pic as your sig, unless she looks BETTER than that girl (dunno if she does or not, though even if she did girls pick themselves apart constantly, so even if they look perfect they still think they arent good looking) then she'll probably always be worrying if you'll leave her for another girl who looks better, or she'll just feel worthless cuz she doesnt look like that, since youve said without saying thats what you like since you have it there on your sig.
Most girls wouldnt even admit to this, i dunno why, but its true. For some reason alot of girls will just let the damage build up, never say anything and act like theres nothing wrong, then you end up finding out later after they've been being hurt by it forever what the problem is.
Btw this isnt one of my serious business posts (inb4 sidewinder or ziggy debating what i just said) but all the same, a girls feelings and self esteem is probably the most delicate thing in the world. Even the most innocent thing like "hey, this is pretty good!! (referring to dinner)" has a good chance of being heard as "wow im suprised i thought this was gonna suck(ie i didnt believe you could do anything right)"!!!!
Welcome to the minefield lol, the earlier in life you're better equipped to be a better guy, the better. Cuz guys and girls really are like from two different planets with how they see things and interpret them.