What to say

the other day one of my friends was talking about going to a kenny chesney concert. he said one of the reasons was for the view(ie. the pretty girls that are there to see kenny). another of my married friends had this to say 'it doesnt matter where you get the appetite as long as you come home to eat'. obviously saying its okay to look at other people but as long as you stay faithful to your spouse everything is okay.

it makes me sad to hear such comments. i am worried about my friends marriage. it is a very dangerous and slippery slope to accept such logic as sound and factual. what do i say to that? do i say anything at all? i feel like i should say something but not sure what.