how do you feel about a 28 year old dating a 43 year old?

im 19 my mom is 43 and she recently started dating (?) this guy thats 28 years old. to me this is just sick and honestly pathetic to me from both sides. from my moms side, how can you date someone thats basically young enough to be your kid? my cousin that we live with is literally 26, my aunt is only a few years older than my mother

from the bf perspective, how sad are you to not be able to find someone your own age? i think that it shows how immature you are, its like you need a parent with you. i honestly dont want anything to do with them, its just so gross to me and i try to refrain from rude comments