If your spouse is into something you don’t ‘get’ or understand, don’t jump to making fun or questioning it. If they think something is ‘cool’ or ‘cute’, you can simply let it be.
Firstly, understand that it may just be a gender thing; men and women often appreciate things differently. Beyond that, people just have varying tastes.
Let them enjoy their thing without making it a big deal. You don’t need to comment on everything they say or like. Choose your moments for disagreement or playful teasing wisely.
If you’re genuinely curious, later on, you can ask them about it – with respect and curiosity.