Why won't husband shower?

We've been married for 8 yrs. At first, my husband showered/bathed at least every other day. Now for the past 6 mos. he'll only shower once a week, and that's if I bug him to do it! He won't give me an explanation why he doesn't. I've even gone as far as not sleeping with him, until he does shower! He sweats a lot too and that doesn't help our sex life, because I won't have sex with him unless he showers first. Please help!