HELP I got on top and it was uncomfortable??

So me and my mans been messing around with positions, and recently I got on top for the first time. He was laying on his back and I was riding. But it didn’t feel comfortable. It didn’t hurt or anything, but all these girls are telling me it feels so good. But and I the only one who feels like the angle is weird. Like it slips out lmao, and it’s not like he’s too small or anything. Idk am I like doing it wrong???? Someone help.