So my fiance's father likes to flirt, as told to me by my mother-in-law in passing when telling a story. He hasn't been physically inappropriate and they've been married 44 years so I'm not taking it as anything more than joking around. It makes me kind of uncomfortable, though, but to me that's just more on personal differences than anything else. Ideas? I.e. they're right now on a trip together and first he sent me a message asking about snow and saying my fiancee was still asleep so I was all his and then a message that he's up so I'm no longer his (that "level" of flirting). Yes of course I can bring it up to my fiancee but I mean it doesn't bother me that much in the sense that all I'd do is ignore it and not respond but I don't want to be rude either. How to approach this? I don't want to make a mountain out of a molehill but I also would like the flirting to stop. Thanks for any suggestions