Getting tougher by the week

I am what most people consider a happily married man with a wife who loves me or so she says. The reason I say this is because she openly admits having affinities to others who are similar to myself but denies it when I mention it. Its as if she wants my character but just not from me. We get along fine however she is in a state where she doesn't want to be physical at the moment. Well I'm okay with the fact that marriages tend to go through these phases, however I am finding it difficult to deal with. In hindsight I feel that she is no longer interested and there is nothing worse than when you feel neglected at home but other women want to be near you. Its like a double negative on one side you want to honor your vows but it gets difficult when you end up sharing your day with women who have an interest in you. I know like any relationship it always tend to be strong in the beginning and may deteriorate over time. I don't want to throw in the towel but if you're in need and someone is willing to meet that need how long can you continue to act as if you're not interested.