Bingowings said:

My cousin's wife is older than his mother (her children from her ex-husband are older than him) which is a bit unusual when you are introduced to the situation but no more than the vibe he gets meeting my partner (there's 11 years difference between us and we are both men).

I think old guys with younger women don't get anywhere near as much attention (usually it's the woman accused of being a gold digger that's the knee-jerk attention of gossip).

I have a similar situation. My cousin is about 40 years older than me. He's ~10 years older than my mother, who is his aunt. My mom was the youngest of her siblings, and my cousin came from her oldest sibling.