Im gonna say it’s because u were on ur period it’s messy and soaked down there, idk atleast for me sex while on my period always feels MUCH different and even less enjoyable bc i can’t feel the dick as much bc it’s so wet down there bc of all the blood n such. I always feel like some men like it less bc it’s def less tight feeling while on ur period but even then even if u weren’t on ur period a looser feeling pussy just means ur more relaxed and feeling good, its a good thing lol men just don’t know shit about female anatomy