Simple question about Deleted chats

EXPLANATION: so a series of circumnstamnces have brought me to having to recieve a message from a contact that, i just found out, i blocked some time ago. i cant see if i recieved the message because of the block and i feel like if i ask for confirmation about the content of the message and he already sent it he will then catch on the fact i blocked him, without me being able to argue against that and so he will get upset at me and cause some more family drama. so i plan to ask another person about his contact pretending i had lost his number which, with some BS on the spot, will prove my innocence. TLDR, can i delete a chat without the other person knowing? like will it give them an allert or any signs? (delete it so i can then pretend i had lost the number and save my ass)