Be open, and tell him (yet again) that your machine works fine.
My DH, when he found out I needed a sewing machine (just married), decided to get me in on the process, since he knew nothing about sewing. He took me to the dealer and let me pick out a machine. I have been using it nearly 30 years. (I have picked up a featherwwight to carry to classes, also.) Just a few days ago, he asked if I need a new sewing machine, thinking to replace my first machine for our anniversary. It took a lot of convincing to get him to give up the idea. He has always put the value on 'the newer the better' philosophy. :lol: I asked him to save the money until I find a machine that does something better than mine does!
I like the idea of asking for a gift certificate for fabric, instead.