It's ridiculous on it's face to expect someone to be physically attracted to anyone else no matter what happens.
then don't ever get married. if all it means to you is until someone better comes along or until your wife is no longer attractive to you then do everyone a favor and skip it altogether...
you're going to get old dipshit... if you're lucky...and everything that comes along with it.... /insert war and peace length diatribe here\
do you think old/fat/ugly people stop having sex
or that their attraction to each other is somehow perhaps deeper than your current understanding, maturity level, intelligence or complete lack thereof can comprehend?