First of all you should not be worried-you are way prettier than the blond!
But I would'nt say he looks happier with her anyway, just a different
kind of happy. If he has self esteem issues then he was most probably very flattered that this other girl posed for a pic with him, she gave his confidence a boost, thats all. If anything I'd say he looks a little embarassed. He looks way more comfortable in the pic with you, leaning towards you, cuddling up and wrapping his arms around you. Men can be idiots, lets face it

(Sorry guys)

They don't realize that sometimes situations that are unimportant or trivial to them might have a huge impact on us, whereas women tend to consider their mans feelings
alittle more. I hope you guys are gonna be OK, it sounds as if you really love him, my fella has been a prat many,many,many times!LOL!But you have to forgive 'em, afterall they
are men!