Anal sex gone wrong 😁😩 TMI

So we were having sex and having fun and then he said he waNted to hit it from the back and I was okay with it. So I turn around and he started and it hurt, but idk It wasn't horrible. Anyways, after a while it started to smell like shit. And I was low key freaking out, but there wasn't really anything anywhere. I didn't say anything because idk I thought it would be awkward and he didn't either. And we stopped and then went at it again. And then stopped and we were making out and he wanted to go again, but I didn't because it kinda hurt. So I rode him and then got dressed and he went to go drop me off at my car. Everything was normal on the car ride there. When I got home I went to the bathroom and saw (THIS MIGHT BE TOO PERSONAL) some stuff on my underwear not a lot, but it wasn't there before so I'm assuming t just all came out after he stuck it in? Like I didn't shit myself but it smelled bad and I'm just freaking out because I showered before I left and everything. So is this normal? Like do they get grossed out? He hasn't texted me yet either.. And we talk all the time.