Difficult to answer this one without knowing a bit more about your circumstances. If you have young children, that provides an easy excuse (unavailability of baby sitters etc.) Aged parents, ditto.
If it's inevitable, then do the "boss" thing; make a conspicuous appearance early on, and stay for 30 mins or so, then make polite excuse and leave.
I hesitate to wonder why they don't like you - is it an active dislike, or do you just not "fit in"? I've had some of the latter, for example being the only youngster among an office full of older people (and now, in my case, it's the reverse). There sometimes tends to be an "office culture" and if you don't follow it, you become ostracised.