Weird feeling during sex

Okay so this is gonna sound really dumb but I just want to see if I’m the only one...

I’ve only had sex with two guys, one I was in a two year relationship with and the other I started dating a month ago. This new guy is a bit bigger down there than my ex is and when we have sex I get this weird feeling in my butt like I have to poop or fart lmao.. like we’re not doing anal or anything, just regular vaginal sex. Is this cause he’s bigger so he’s filling me out more? Anyone else feel this? It’s really distracting and makes me super paranoid that I’m going to fart while we’re having sex...

Sorry this sounds so dumb 🙈