I know my mom dates. My parents divorced a year ago. My mom joined a dating site, but when I asked, she denied it. She still has it on her phone. She gets texts from a man, who I met, under the cover of 'just her friend,' which are CLEARLY not platonic. She gets valentine's day and anniversary cards from him, and shamelessly displays them.  But when I confronted her, she completely denied it. To this day, she remains clueless that I know. I understand that moving on is natural, but she refuses to admit it, and it breaks my trust in her, knowing that she doesn't think I should know. She thinks she's sneaky, but I know her secret.
TL;DR version: My mom dates, and lies to me about it.