Is it normal to be in this kind of sexual action?

So since a lot of you didn't check my previous post, even though it's a pretty common title "My girlfriend." I thought I might as well share with all of you what kind of relationship I'm in at the moment.. So, alright here it goes, also this is one of the situations i've been in.. there's much more..

So, I was with my girlfriend alone in the park one day and we decided to have sex. Thing is, she has this really weird fetish about seamen, saying whenever a guy ejaculates in her mouth it's a ritual of saving the soul from the devils clutches. It creeps me out, BUT whenever I ejaculate in her mouth she does some weird chant and it creeps me out because while she's doing that weird chant she also rolls around and it looks like she's having a seizure. I'm not sure what to think anymore.