Hes still stuckon his ex fiance

My husband and i have been together for almost 3 years and married almost 2 and i was just scrolling his Facebook page. He was sitting beside me and knew it.. i saw where he had searched his ex fiance up on there .. I confronted him about it.. he said it popped up randomly in the people he may know. But why would it be in the searches and visited part of the page ? He also brings her up in random conversations we have. Should i just let this be curiosity or should i end my marriage. Really torn right now. Please help