DH encountered this, not me, but I'm so proud of how he handled it I just had to post! For the purposes of the post, DH will be Lord Snowdon, and his dad will be known as The World Revolves Around Me (aka TWRAM).
So Lord Snowdon and TWRAM went to an event together, involving dinner and a talk about some aspect of how terrible the world is now. Before dinner started, TWRAM said to Lord Snowdon, "When are you going to have kids?". Lord Snowdon said, "Not right now. Have you decided what you're having for dinner?". TWRAM said, "Cause I want more grandkids, and we can't assume your sister will have anymore, so when are you and Lady Snowdon going to give me more grandkids?" Lord Snowdon said, "We're not planning on kids in the next couple of years. Have you heard this speaker before?". TWRAM replied, "Well, the two of you aren't getting any younger! You need to start now, before you're too old!". Lord Snowdon said, "We haven't decided anything right now. Did you hear about the new Vikings stadium proposal?", and finally got TWRAM off the subject of our reproductive choices.
Even a year ago, Lord Snowdon would have felt obligated to tell his dad that we're not sure we actually want kids, and we're trying to make sure we're financially able to take care of kids before we have them if we do decide to have them, and so on and so forth. Now he just moves on to the beandip after a quick non-answer!