what's infidelity

My husband says it's not real. but it is. I'm feeling the effects of it. Maybe it's on the low end of infidelity, if that even exists. Online emotional infidelity, taking private pictures, opposite sex friendships that don't know you're married, exchanging "I miss you" and "I love you". Those words in the context they were used belong inside the marriage. They literally laughed at me becuase I accidentally saw the pictures after my husband passed out and quickly realized what was happeing. It wasn't just pictures or instant messages, it was voice messages too. Over 10 years of marriage- together for almost 14 years. Three children ages 5 and twin 4 year olds. I feel like i'm the trash.