Am I overreacting?

Yesterday was my FILs birthday so my husband, my 5.5 month old and I pretty much spent the whole day with my inlaws. Through the course of the day I found out that my inlaws have been giving my son solid food without my knowledge (I have started him on solid food but am doing it slowly), have given him Popsicles, and told my husband to not tell me about it. Yesterday my SIL tried to give my son some cake but I stopped her and she just laughed and said I was being ridiculous for not giving him some cake. I feel very disrespected because they are telling my husband to go behind my back and lie to me and they are introducing new foods to him without my knowledge. My hormones are still crazy so I don't know if I should just brush this off as something grandparents do or are my concerns rationale and I should say something? I have had a rocky time with my inlaws since my son was born and don't want to start something unless it's justified.