Is texting other people of the opposite sex flirtatiously Cheating or entertainment?

I'm in a 2 year relationship and my boyfriend texts his ex and other women from time to time on the phone and social media. Needless to say this always causes conflict when I catch him. He claims he has never cheated physically and that it's only entertainment but it hurts my feelings and makes me feel as if he may be hiding other things. Open to honest opinions from those who experienced similar or people who entertain others through text,social media while in a relationship. PLEASE be genuine and not rude..thanks