So I like my office job and I would like to keep it, thats why I usually avoid work relationships(and also because i have a girlfriend already), but this female coworker comes to my desk everyday and talks to me for a while, I thought it was normal until a few days ago when she started asking me about my girlfriend, why we didnt have kids, and then she told me she likes dating younger men (she is around 40 years old and I am 30) and tells me she has a date with a 26 years old on friday. I congratulated her but it felt a bit weird, should I tell her something so she backs off? or is doing nothing enough?