There's nothing actually unethical about it if they're both legal adults. Personally, I couldn't picture myself dating someone who's old enough to be my dad, but I'm okay with others having a large age gap.

30 years

Nothing younger than 21. Drinking, etc. nothing older than 50. xD

35 years older max.

Generally my rule is that he needs to be closer to my age than my parents' age but I can make exceptions under certain circumstances

10 years yet i still keep sleeping with men in their 30’s and 40’s

For me, I would prefer similar ages to myself and staying within like 3 or 4 years either way (i.e 18-24).

edit: I'm answering this based on personal preferences, I don't have an opinion on others' preferred age gaps.

Sis, try dating someone older than both of your parents, feels amazingly liberating

Anyone over 20 is good, for dating anyone. I'm saying that as a 23 year old though, not as an old man.

I'm into older men, like 30 - 50, but i do slightly judge them for being into me.