Back when I was in my 20-30's I did a lot of office work, and found that the 'pity party' was often the reverse. This is what I mean:

Setting: Chit chatting with co-workers at coffee break

Co-Worker #1: "I have SO much to do tonight. I have to pick up (insert Child's name) from school and get her to piano practice. While she's there I have to go home and get (insert Child's name) ready for football practice while I put dinner in the oven. Then get (Child #1) and she'll have to come to football with us. I won't get home until almost eight o'clock!"

Co-Worker #2: "Yeah, I know. I have to leave early to pickup my son from daycare and get him to the doctor by five. I hope they're on time, because my other son has swim lessons. What are you doing tonight, Karen?"

Me: "Well, my husband's working late tonight, so I think I'll have a hot bath when I get home. Then maybe have a glass of wine and read until he calls so I can put some steaks on the grill."

Co-Workers No 1 & 1: (said with a jealous tone). "Wow... must be nice!"

You know, for years I just didn't quite know how to respond to that. Eventually, I made up the little lie 'Yes, it's nice now, but when I'm older I won't have family to visit me like you will." That would mollify them. I'd get the (relieved?) nods of agreement and the conversation would be over. However, I always ended up feeling like I 'sold out' because I don't feel like that at all! When I'm older I'll be in senior clubs and have boatloads of friends to do stuff with!

My best friend (also childfree and loving it) came up with a far better response. One day she got so tired of the jealous 'must be nice" comment that she gave a huge, sunny smile and said with enthusiasm "You know, it really IS!"

I use that now, too!