I have just split up with my Mrs after 4 years, partly because I didn't find her attractive any more. So yes - being hot is important. It is only natural that we will want our partners to be good looking, because good looks are usually because of good health, and good health usually means healthy babies
So there
Anyway it's OK, I have a new one now! & she is hot. (at least warmer than the other 1)...
Good job they don't know I come on here eh? Anyway, if the guy knows you & her are together, then yes, you should confront him. Sounds like she is messing you about anyway mate - I'd either tell her it's not normal to do that with other blokes, or get rid of her.