Wood.

I think if you are going to spell something wrong – it should be an all or nothing deal.   Not pick and choose the words you want to short hand, as that defeats the purpose of shorthand.

“Wud u like to see a big penis”

If you are going to be lazy on words such as would and you, why would he not be lazy on to and see as well.   Granted, the answer is no either way – but I think I would be a lot less annoyed if the message had read “Wud u like 2 C a big Pnis?”   – At least that would have been owning the stupidity.

Or of course,  make it a play on words if you want to be lazy and instead of “Would” put “Wood” instead..   Then at least I would have laughed.