Who do I believe?

I left for a week to go to a wedding, my husband said he couldn't get the time off. He told me on Saturday he was going bowling and to the bar with his friend.

Today I had a family member tell me they seen him alone with a women and he told them we broke up. The Family member is known to exaggerate.

He said he was with his friend and his wife, and never said that, but got angry when asked about it. His friend says the same thing. Who do I believe?