Backshots

With my ex I use to love backshots it was the only position that felt good for me. Well I broke up with my ex over a year ago and I met someone. We talked for about a year and we started having sex. Well backshots with this guy is different. It seems like I can’t handle it. When he goes in I immediately tense up and can’t take a full stroke 🙄 And he always goes “why are you running” lmao happens to anyone else?