<human>: A few years ago, my mother (60sF) took a job in another country, and Dad chose to stay behind and take care of the house on his own. They're still together, but long-distance. My sister, Paige, lives near him. I live a fair distance away, and only see Dad and Paige every few months.

He's always enjoyed the occasional drink, but since Mom moved, it seems like he's been stepping it up a little. Paige has come by for weekday visits to find him stumbling, for example.  

The last time I visited, an old friend from high school came by the house, and Dad had been drinking again, enough to slur his words. He complimented her legs - nothing explicit, but it wasn't a comfortable situation.

So, there's the context. Paige just called and told me that she'd visited his place with a girlfriend of hers, and he'd clearly been drinking recently. She said that he'd been "staring at their butts" and tried to give her a sloppy kiss, even though she told him no. When Paige vented to our mom about it, our mom's response was, "Maybe fathersday_throwaway can talk to him about it when she visits. But if he's happy, let him be."

After that, our parents probably had a talk. Paige got an unapologetic email from Dad saying, "I was drinking, but not drunk. I guess I just won't talk around you and your friends any more."

So Paige isn't interested in seeing him for a while, understandably. I'm still scheduled to stay at Dad's place this weekend (U.S. Father's Day), and Mom and Paige seem to expect me to talk it out with him. 

But I've tried to discuss this with him in the past, and he just doesn't see a problem. If I bring it up the wrong way, he might feel like he's being attacked from all sides. I don't really know what I can do, or if it's even my place.

Provide a brief overview of the text.
<bot>: Father's Day is going to suck. I'm supposed to talk to my dad about his drinking/ogling. How to approach?