Should I tell my ex wife?

that I have a GF? I've been pretty much keeping my GF a secret from our co workers and family ( we are both very recently divorced and are being very careful so this relationship has a good chance) My ex wife doesn't know I am dating her but I am pretty sure she has an idea because she knows how close we've always been. I know if I tell my ex it'll get around because she is a leaf blower when it comes to anything...but I am considering telling her because she pops up at my place...she used to ask if she can come over but 2 today I woke up to the dogs making a fuss and looked up and she walked in sayin and I quote " I ddnt go to work today because I had the runs ....so I came her to watch Smallville" ......what if my GF was there when she barged in? I am hesitant to ask her to not come at all - the place is still leased to her and she is going to release it to me in a few days so I don't wana piss her off ...so my question is should I just tell her I am dating now?