[introduction]

Originally Posted by guacadoggie

Where does one draw the line when it comes to interfering with someone's relationship?

The other day I went to my dad's house for dinner; he also had his girlfriend of 1 1/2 years and her four kids over. After dinner my little sister asked if she could speak to me in her room. She showed me her string of im's with this 17 year old girl who's mother was dating my dad. Apparently they've been dating for four months while he was also dating his other girlfriend, whom I like and respect very much.

So, this is where my question arises: should I tell his girlfriend? I don't feel my dad deserves her...

don't tell the girlfriend first, definitely tell your dad you know what he's doing, but don't directly tell him what he should do, you should just imply to him that you think he's doing the wrong thing by both of these women. this way, you don't have to get involved between your father and his girlfriend, and he won't resent you for going behind his back (even if he's a cheater!). if he does nothing about it, then you should take more drastic action, like telling him what you're going to do. remember that there's always the slightest possibility that he's innocent.

[guacadoggie]

So the new girlfriend called him out on this and broke it off with him after her daughter told her what was going on. I didn't interfere at all, even though I wanted to since he did this to my mom a few years ago. He said he was going to talk to his other gf about it. His excuse was lame.

I think my dad has some mental problems if he is repeatedly doing this in different relationships.