Were you being sarcastic? I've heard this before and it's usually considered that once someone gets married/has a family of their own, they simply will have to devote much less time to their profession/'hobbies' (like math) because of time constraints, and then they just start degrading due to lack of practice etc.
One of the times it was specifically brought up in reference to a known mathematician. The takeaway being that getting in a relationship, or even married, automatically disqualifies you from achieving anything of great importance in the future....made me pretty sad that it's such a common pattern of thought.