My 14 year old son went behind my back...

And bought himself a Nintendo Switch Lite after I told him no. Hes been saving his babysitting and chore money, plus got some extra money from my 16 year year old and went out and bought this after mentioning he wanted it and I told him no. The reason I said no is because he currently has 3 Fs in school and has no business playing games when his grades are so low. Last year he was Honor Roll so I know he has it in him to get better grades. His sister is the one who told me he has it, he told her. Now I dont know if I should confront him and take it away until his grades are up or just wait to catch him with it and confront him then. I'm kinda hoping he will come to me and tell me he bought it but I dont think be will. How would you handle this?