I think really many folks have had the piss taken out their looks from the show, look at some of the things said on this thread about some of the women.
I'm not sure I recall Alex having the piss ripped out him from day 1 for being so pale, but I do think everyone just thought he was a doctor who couldn't manage to put on sun tan lotion effectively, hence the piss taking.
His behaviour on the show really hasn't been exemplary, and the way he treated Alexsandra was appalling, he basically dropped her because he fancied Laura more, clearly told everyone that, else otherwise why would jack need to tell him he kissed Laura, and then when he failed to pull laura went back to Alex acting like he didn't know why it all went wrong and taking no responsibility. He dropped her like a hot potato when Laura crane walked in.
I think alexsandra really does like him, that's the sad part, but it's not going to last as he's simply not that into her. He thinks he can do better for some mad reason.
I personally think alexsandras very attractive and don't see Laura crane as any more attractive, but Laura has a much different, edgier, cooler, confident vibe about her, which is what I think was attracting Alex.
In addition I suspect he wants to be seen as one of the lads having his pick of the girls, that he was able to pick and chose, that he was one of the cool lads, who could pull the cool girl, and got it very, very badly wrong.