Why is my cum lumpy😭

My fiancé was going down on me yesterday and he kept having to stop and spit out big lumps and after he ran to brush his teeth he said it was all stuck in between his teeth and tried to say it was just chicken from dinner an hour previous so i wouldn't get embarrassed. Its not like water anymore, the past few times it has been very lumpy which is strange because nothing in my lifestyle has changed. Its really getting me down.......😞