I am a female My best friend is a married man,should i continue or discontinue?

We have never had we just share a whole lot exchange gifts and encourage each other .We however have recently almost engaged ually but it never happened.but he openly claims to love me but he gives his wife the best gifts He may takeme to fine restaurants and hotels so we can spend time together, but he buys her new cars any thing she asked for i have being enraged with jealousy