Microwaving cereal is not a common practice, but personal preferences and habits can vary from person to person. If you enjoy microwaving your cereal and it has been a part of your routine for a long time, there's nothing inherently wrong with it.
Microwaving cereal can have certain effects on its texture and temperature. It might soften the cereal, making it easier to chew, and warm it up, which some people find appealing. Additionally, microwaving cereal with milk could create a similar effect to warm milk on cereal, which is a common practice for some individuals.
However, it's worth noting that microwaving certain types of cereals may result in a change in texture or loss of crunchiness. Also, be cautious not to overheat the milk to prevent it from boiling or splattering.
Ultimately, personal food preferences can vary widely, and as long as it doesn't pose any health or safety risks, enjoying your cereal in a way that suits your taste is perfectly fine. If your son teases you about it, it's important to communicate and respect each other's preferences and find common ground.