"Where is my blue dress?  Where are my best shoes?" (etc)

When you go to a big sale with the joint credit card,
 you might find out that they beat you to it and
 ran up the card to the limit already.

If you wear an outfit that makes you look fat,
 they will actually notice it and will probably tell you.
 (OK, this might be good too ;-)

If you find lingerie in their glove compartment,
 chances are it might be yours!
 And it has been worn!  Ewwwww.

When you pull out your best stockings that you carefully
 put away for that special evening you had planned, alas
 you find that they have been moved and now have a run
 in them.  *sigh*

There is always that worry that when you have sex,
 s'he might 'fake' an orgasm in the endless pursuit
 of being "as femme as possible".

If you go to a singles bar hoping to save money,
 s'he might get more drinks and phone numbers than you!

If the above happens, you might actually miss having
 your butt pinched, fanny slapped, legs whistled at, etc.

When you comment out loud that your 'hips look fat' -
 they might get so jealous they won't talk to you for a week.

Their fake breasts might actually look more appealing
 than your real ones.