Dad or stepdad to walk me down the aisle?

When I asked my stepdad to walk me down the aisle he said he would be honoured but if it caused a problem he would gladly step aside. When I asked my Dad and told him I wanted both him and my stepdad he told me I had to choose one or the other because he refused to share it with anyone. My stepdad has only been a part of my life for the last 6 years but in that time I have become so close to him and feel like he is a second father to me. I feel like my father is putting me in a lose lose situation. Either I have him walk me and regret not having my stepdad and resent my father for making me choose. Or I tell my father where to go and risk not having him there at all and possibly never see him again. He has always been quite a selfish person and this is no different. He is more worried about his feelings than mine on my wedding day.