“Shall I date him or his best friend?”

About two months ago, my best friend since childhood confessed that he’s liked me for the last couple of years. Me, being myself, decided immediately that I wanted to preserve the friendship. We were the type of friends that both had really busy schedules but we’d hang out for hours and be at each other’s houses till the middle of the night.

So after a while of thinking things through, I decided I wanted to try a relationship. After informing him, he repeats that he doesn’t want to ruin the friendship and that he’s talking to a different girl. I know that he takes a long time to get over people in general so I’m unsure why he’s going after a different girl. I don’t know what to do. Should I hope for him to eventually stop liking her or should I get over him and date his best friend?